Information

Help ID this plant, quite possibly a weed

Help ID this plant, quite possibly a weed


We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

I found this plant near my South Indian home in Kerala, India. Most probably it could be some sort of weed. Anyhoo, is this plant of any medical or commercial value? Is it a remedy for something?

  • It has a white tap root with little veins off the main root
  • It has a really small yellow flower
  • It's leaves are similar to that of a clover, except for that it has three to five leaves

Merci d'avance!

(P.S. Forgive me if this is some very common plant that I should know about, I'm in 7th grade.)


I presume it is Cleome viscosa, the Asian spiderflower.

It is commonly found in rainy season.

Medicinal uses:

The crushed leaves have been investigated as a treatment on stored seeds of cowpea, to prevent weevil infestation.

The leaves are use as external application to wounds and ulcers. The seed are anrhelmintic and carminative Juice of leaves is used as remedy against discharge of puss from the ear.

Identified by the following features-

  1. Palmate leaves

  2. Colour of flower especially the brown part at the base

  3. Herbaceous habit

References:

  1. Wikipedia
  2. Flowersofindia.net

Weed Identification and Control

A weed can be any plant growing where you don&rsquot want it to. They compete with other plants for nutrients, water, and light, as well as harbor diseases and pests. On this page, you&rsquoll find information on weed identification and control, including catsear, marestail, purple loosestrife, pokeweed, pigweed, poison ivy, crabgrass, hemlock, purslane, and multiflora rose. You&rsquoll also find tips on using various herbicides and integrated pest management.


That looks like a squash of some kind. It will probably send out runners and spread quite a bit. The fruit should be edible, but I can't really tell what it will look like. It may be more like a pumpkin (it resembles Cucurbita maxima).

It looks like Hollyhock. The stems will grow tall with beautiful flowers

Do you eat cantaloupe or muskmelon at your house?

A few years ago I used some compost in my flower garden and surprise! I had a plant similar to yours growing amongst my marigolds. I let it keep growing, very sure it wasn't a weed. Like others have mentioned I thought it was a squash or cucumbers. It ended up being a muskmelon. We eat it for breakfast a lot and so some seeds had ended up in the compost, then my garden.

Unfortunately they require quite a long time to grow (80-90 days above 70 degrees F or something like that) so I never got to eat one of them. (I live in New England, so I would have had to start them much sooner and kept them warm)

Let it grow and see what you've got. If it is a muskmelon, and you're in a more friendly zone for melons than I, pinch off all but one or two fruits so they are nice and sweet, and keep them on pea gravel or elevate them off the ground some other way so they don't rot on the soil. Once they start to ripen (you will see the flesh beneath the web-like texture start to turn orange) only water enough to prevent wilting, to further increase the sweetness.


Preparing a Herbarium: 8 Steps| Plant Taxonomy

The following points highlight the eight main steps to be followed for preparing a herbarium. The steps are: 1. Rules for Herbarium Plant Collection 2. Tools and Equipment’s 3. Identification and Classification Back at Home 4. Setting the Plants Up 5. Special Treatments 6. Drying Plant Specimens 7. Mounting of Specimens on Herbarium Sheets 8. Herbarium Organization.

Step # 1. Rules for Herbarium Plant Collection:

(a) Almost all natural environments are suitable for searching of plants for the herbarium. So, places, which could appear sterile and dry, must not be overlooked. Only native and naturalized plants may be collected.

One may rely on the richness of the flowers and plants, which grow on grasslands and prairies, but one may also find an interesting specimen during trips to the mountains, swamps, coast, woods or wherever the climate and the temperature are not too extreme for plant survival.

However, collecting on private property, or National parks, or private farms should be avoided. In such cases, it does require prior permission from the owner or local administrative office. Further, some species of plants are protected by the law. So it is not wise to pick them up from the environment.

Some rare plants are protected in the whole territory of some region or districts. It is the responsibility of the plant collector to get a list of the protected species and one should get permission to collect these protected species too. One can also substitute colour photographs for samples of the protected species.

(b) One should avoid collecting all of something and the last of anything i.e. in general, a good rule of thumb is to collect only a small set of samples from a large population. It is wise never to pick up an excessive amount of specimens of the same plant, especially if one does not see many of them around. It is advised to harvest the minimum number of plants one needs for classification and collection.

In case of annual plants, a similar guideline is usually well to follow, but for trees and shrubs, it is best to selectively trim a few pieces from different individuals so as not to damage, in any way, the long-term survival of any individual.

(c) The most important part of every collected specimen is the flower. So the best seasons for picking up plants are spring and summer. However, certain species show their flowers in autumn or even winter. Hence, the colder months should not be neglected for excursions.

At the same time a few plants have a very short blooming time, which one should keep an eye on to catch the flowering time. Some plants have short-lived flowers, which are deliquescent and will break up in pieces, unless picked early in the day and immediately pressed in the folder.

(d) The plants which one is interested in should be fresh and not wet (apart from plants which live in aquatic environments). The most convenient specimens to pick up are those, which seem quite dry, and lacking any trace of surface moisture.

For this reason, it is better not to look for plants during rainy days, or early in the morning. Also, the hottest hours during summer days should be avoided, as plants will not show their freshest appearance.

(e) While collecting annuals, one should attempt to gather roots, flowers and fruits. Some species may also require fruits or mature seeds for identification, as for example, Brassicaceae require fruits for identification.

One may bring along some small bags or envelopes to carry the seeds and other small separate components. Sometimes during some particular excursion, one may happen to pick up the plant when the seeds are not yet formed.

In such cases it is advisable to return to the same place some weeks later, hoping to find some newly grown seeds. Similarly, while collecting a biennial, both the first and second year forms are useful, but at least flowers are required (again, Apiaceae requires fruits). As for herbaceous perennials it is best to avoid taking the root system.

A small piece of the root, or a single bulb, may be necessary for proper identification in some groups (Poaceae, Liliaceae). When collecting members of Poaceae, Cyperaceae and Juncaceae, for example, it is advised to make observations regarding rhizome, the presence of which can be critical in the identification of the plant.

Many other groups may have stolons or rhizome, and while a piece of the stolon can easily be gathered, the presence of a rhizome in some other groups might better be just simply noted rather than collected. All dirt should be removed from the plant after collection as well as all the insects, spider-webs and foreign bodies attached to the specimens.

(f) When collecting trees and shrubs, reproductive structures are vital. Cones, catkins and similar structures need not necessarily be new. However, every effort should be made to collect fresh flowering and fruiting parts if possible.

Several species will actually flower before leaves are produced. Such individuals may be collected, but for proper identification m some groups (for example, Fagaceae), leaves and even mature fruits may be necessary.

(g) A herbarium with scientific merit usually relies on the plants, which grow naturally in a specific geographical area. So it is important to distinguish between the wild species from those, which have grown after human intervention, as for example some garden flowers or most cultivated plants.

Occasionally it has been found that a plant species previously introduced by man may continue to spontaneously grow outside its original artificial environment. In such a case, the plant can actually become a new element of the spontaneous flora and can consequently become part of a herbarium.

(h) When one picks up plants from the natural environment, one should keep in mind that the plants have to be fixed up on returning home and they will have to be classified too, in order to achieve a scientific value for the herbarium. These operations require a substantial amount of time.

Hence, one should try not to collect so many specimens that one cannot find the time to settle and study all of them. Further, during classification, o < i.e. may have to section and basically tear apart some flowers.

Hence, it is suggested not to pick up just one or two flowers of each species while looking for plants, otherwise one may be forced either to sacrifice every flower for the classification job or to simply give up the classification.

Step # 2. Tools and Equipment for Preparing a Herbarium:

The following are the essential items or equipment, which are indispensable for plant collection:

The collected specimens should be put into a strong bag made of cloth or polythene or similar material (plastic, etc.)- The function of these containers is to protect the plants from damage during the outing. When collecting in plastic bags, the specimens should be folded to the correct length for a herbarium sheet and placed firmly, but carefully, into the bag. They should not be just dropped in.

This will prevent entangling of separate collections and there will be less damage. Later while emptying the bag, it should be turned upside down. The material should not be pulled out of the bag. This usually breaks up the specimens. It is preferable to use large bags rather than small ones, as there will be less damage to the plants.

If one collects large, heavy plants, it is best to put them into a separate bag as they may damage other more delicate plants in the bag. This is especially true for palms and large aroids.

To prevent significant wilting, plants may be wrapped in moist newspaper and placed in a plastic bag, which should be kept shaded. When mass collecting in tropical areas, this is not always feasible. Small delicate plants should be placed inside smaller bags.

b. Folder or Plant Press:

If the excursion takes place in summertime or lasts for two or more days, it is better to bring a folder of approximately 45吚 cm or more, or the plant may be pressed after reaching home, whichever may be convenient for the collector. However one should keep in mind that a good specimen is made in the field, not in the herbarium.

It is therefore necessary to keep in mind what one is pressing in the field and how it will look on a sheet of herbarium paper. The folder must be made of cardboard or some other strong stuff, e.g. aluminium, and it must contain some old newspapers. The folder can be covered with cloth and it should be closed with straps or belts, and a handle or shoulder- belt should be added for easy carrying (Figs. 4.1a & 4.1b).

The folder could be made in some different way too, for example a couple of plywood boards containing some newspapers and the boards can be kept together with some large rubber straps or ropes. Blotting paper can be used instead of newspapers, but the latter is much cheaper. The picked specimens must be arranged inside the folder between a few layers of paper, so that every plant has some paper on both sides.

The closed folder does not have to press the specimens too firmly between the newspapers. If the plants are fleshy, more newspapers are needed, and one can also add some additional cardboard inside the folder. A large waterproof bag can be carried too to carry aquatic plants and can be used to cover the folder in case of rain.

(ii) Camera and tripod:

In order to substantially enrich the quality of the herbarium, not only aesthetically, but also from the scientific point of view, one may take colour pictures of each plant in its natural environment. In that way the dried specimen can be placed together with one or more photographs, which can be particularly very helpful for bulky plants like trees or bushes, which obviously can not be entirely included in a herbarium.

Also the habitat of a plant can be well described with a photograph, taking care not to be too distant from the nearby bushes or trees. The suggested equipment is a 35mm single lens reflex camera, with a standard lens and a macro-lens, the latter very useful for close-ups of flowers and other specific features.

Also a tripod can be very important if many close- ups have to be made, allowing the camera to remain steady. A tripod can also alleviate the need for a flash, which may be used when taking pictures in low light, but has the disadvantage of giving quite unnatural looking images. The speed of print films can range from 64-100 ISO to 200 or 400.

(iii) Field notebook:

An important part of plant collection is recording of field data at the time of collection, which can actually increase the botanical knowledge of certain geographical areas. Hence, it is a good idea to write down, various information regarding the specimens one is picking up. These notes will not only help the identification of the specimens, but also can be compared and added to the current botanical knowledge.

For this, special types of permanently bound, pocket-sized notebooks are used. Each book should have at least one hundred leaves, which are serially numbered, and six detachable tags should be on each page, which have the same number. These tags are tied to the specimens of the same kind, which are collected at the same time and place.

The data such as the field number of specimen, date of collection, the locality, the habitat, the botanical name of the plant (if known), the flower colour, abundance, variations and the associated plants, the vernacular name and the uses if any are recorded in the field note book at the time of collection.

The following is a list of what one can record in the field notebook at the time of collection:

a. Collector’s name, associated collector’s name(s).

b. Collector’s sequential field number (must be unique).

c. Collection date.

If possible one can include .the longitude and latitude and also a sketch map is useful.

e. Habitat and ecology:

Terrain characteristics, vegetation type, association with other plants.

The overall size and shape of the plant (tree, bush, epiphyte, etc.) should be described.

g. Field identification (family, genus, species if possible).

Height and diameter colour, texture, thickness and hardness the presence of thrones and spines.

Deciduous or evergreen colour, texture and overall aspect orientation exudate or presence of glands.

j. Inflorescence and flowers:

Note of everything that could be undetected in prepared specimens colour heterostylous, monoecious or dioecious different behaviour (open / closed) during the day exudate or glandular pollinators, etc.

size, shape, colour, texture smell, etc.

Take some samples or describe them (size and shape, tap root, tubers, bulb, etc.).

Record any particular scent, especially of cut parts and flowers.

Note the colour, smell, consistency, etc.

The locally used name(s) may be recorded.

The uses may be recorded after getting confirmed.

Step # 3. Identification and Classification Back at Home:

All collections should be identified and classified as soon as possible. Any seriously considered collection of plants must report the most exact taxonomic denomination for each specimen, along with the date and place of collection. The name one should apply to a collected plant is the scientific name, a Latin noun, which, represents the only denomination that unequivocally identifies the specimen.

To classify every plant one picks up, one needs books that will describe all the species (and hopefully the subspecies too) of plants living in the region of one’s interest. This kind of book usually includes only black and white pictures, often drawings, and focus on all the parts (fruits, flowers, roots, etc.) that can help to classify a plant. There are various books available for the classification of plants.

Some are very complete and expensive, others are handbooks reporting only a particular group of plants (e.g. from a certain geographical area, or from a typical habitat), while others acquaint the reader with every kind of plant with little or any limitations, but they may not actually cover all the specimens one may find during travels.

During identification back at home, one has to carefully examine very small and complex parts, like flowers, internal features and little seeds. One will need some very important instruments such as a magnifying glass, tweezers and a cutter for this purpose.

Good field notes enables one to recall height of the plant and other observations made while collecting. It is a good idea to record the number of sepals, petals, stamens and note the condition of the ovary. Whether, the corolla is sympetalous, or if the stamens are epipetalous, and also the nature of any zygomorphic condition may be noted.

Sketches of the flower made in the field are often extremely useful. It is also important that one finishes the classification work before the plants start to wilt. In fact to compare the specimens to the books descriptions, one must hold fresh plants. Otherwise the identification work could become very difficult and maybe wrong in the end too.

Using an appropriate manual, the family, genus and species of the plant should be identified, adding the author to the binomial. If it is a subspecies or variety, then the infra-specific name and authorship should be recorded as well.

Step # 4. Setting the Plants Up For Herbarium:

One of the most difficult steps while pressing a plant is gaining the right arrangement of the specimens in the herbarium, as when the specimens are placed into the press they will acquire a shape and appearance that will last after the drying process, and so be similar or identical to the specimen’s shape in the herbarium.

Because of size and thickness limitations, it will probably be necessary to remove certain branches, leaves and bunches of flowers, or to carefully section them. This delicate job should be carried out with the help of a knife and tweezers, trying to arrange the flowers in the best possible manner, letting them show the most natural shape and all their features.

During this process, care should be taken to avoid the elimination of relevant elements, especially those, which were important for the taxonomic classification. Any loose part may be kept inside paper envelopes, which will be placed on the same mounting sheet as the specimen. Each species should also display both sides of its own leaves.

If only one leaf is available, one may cut off a part, so that the other side can be observed. If there are more than one flowers available, one can arrange some to show the back of the flower also. Depending on the size of the herbarium folders, one will be able to dry more or less large specimens. Some plants will have to be cut or bent, due to its excessive size. A stem should be bent at an acute angle.

While arranging the specimens on the paper layers, various plants can be placed on the same piece of paper, but care should be taken not to superimpose two or more specimens upon each other. It is better to choose specimens of the same thickness so that the pressure on that layer will be equally distributed.

If rather thick parts have to be placed in the press, an uniform thickness may be achieved by placing some pieces of papers near the more thick elements, so that the layer with the plants will have approximately the same height.

Step # 5. Special Treatments:

Some particular group of plants must be specially treated to achieve a good drying and durability:

(a) Cactus and succulent plants must loose their high percentage of water before being put to dry. To do that they must be placed below some blotting paper sheets, on them a hot iron may be passed rapidly. That must be done a few times, always changing the blotting paper.

Before the iron treatment, the softening of the cactus can be aided by the immersion in boiling water for half a minute, taking care to avoid immersing the flowers. Instead of boiling water one can employ diluted acetic acid or strong alcohol (20 minutes) or formalin (1.5 parts formalin, 1 part water). Since, most cactus, are really bulky and fleshy, it is appropriate to just keep and dry sections of the whole plant.

(b) Some plants have tubers or bulbs as roots, and they must be treated before drying. As with cactus plants, a few minutes in boiling water softens the parts. Care should be taken to immerse in water only the roots that are to be treated.

(c) Many plants have some (or all) parts, which are so bulky that it will be possible to dry only a longitudinal section (e.g. of the stalk or the inflorescence). Hence it may be necessary to eliminate most of the internal parts and pulp, leaving the external features untouched.

(d) Conifers and heathers generally loose the leaves during desiccation. To prevent this the use of warm paper is suggested, adding some passes with a hot iron. It could be helpful to put the specimens in boiling water first, then drying them as fast a possible.

Before the drying process, the small branches and the leaves can be smeared with diluted liquid universal glue like Vinavil (glue used for plastic, wood, cardboard, leather, etc.).

(e) Many flowers change colour in some way during the dyeing process. This may not be any real trouble for the herbarium. But some flowers show a dramatic change, particularly some violet, blue and red petals. To prevent that problem it is vital to achieve a fast desiccation, with many changes of the paper sheets.

Other suggested methods are to put the drying plants in contact with salicylic acid sheets (the sheets previously wetted with a 1% salicylic acid solution). Another practice is to immerse the flowers in petrol (American equivalent : gasoline). Then they must be air dried and finally treated with the paper sheets as the other flowers.

(f) Some plants have rather fleshy flowers (some orchids, iris, lilies, etc.) that must be filled with cotton wool before being put to dry. Every time the paper is changed, the cotton wool should be replaced too. The parts can be dried separately and then the flowers may be reassembled with the help of gum Arabic.

(g) If the flowers are likely to stick to the folder and break when handled, one can detach them and dry them apart using tissue or non-absorbent toilet paper, opening their folders only when the flowers are well dry.

Step # 6. Drying Plant Specimens:

After identification of the plant, one must hurry to go on to the drying process. It is best to work in a dry and ventilated room, avoiding damp, which could easily harm the specimens. Flowers and other plant parts must be dried up into a peculiar kind of press.

It is not difficult to build a home-made press for that purpose, keeping in mind that what must be accomplished is to keep the specimens squeezed between layers of paper (newspapers or blotting paper), until they are totally devoid of the original content of water, that is dried.

As for the folder previously mentioned, the upper and lower parts of the press might be made of heavy cardboard or thick plywood or equivalent material. The specimens should be placed between the layers of paper, which should be pressed, by two pieces of wood. These two pieces must be held tight by putting some heavy body on top, i.e. bricks or large books (Fig. 4.1c).

It is important that the plants are put under sufficient pressure, otherwise more time will be required to achieve a good desiccation, besides they could be damaged by dampness and moulds. Every specimen in the press must be linked with its own written data. The best one can do is to use a tag for each specimen, which can be attached with a string.

As circulating air is very important to get the specimens dried in a short time, it is better to add some corrugated cardboard sheets between the paper layers, so that some air can penetrate and speed up the drying process. Corrugated aluminium sheets are even more effective than cardboard.

Bulky parts can directly be placed in contact with corrugated material to speed up drying. If no such material is available, the filled press size should be kept small. Instead of newspapers, some recommend the use of blotting paper together with tissue paper.

A more advanced kind of press might be built for an optimal drying of the plants. This press can be made with two wooden boards with screws and nuts placed at each corner. Turning the nuts, the two boards will come closer pushing together the paper with the plants (Fig. 4.1d).

The press should be exposed to a gentle heat source, avoiding excessive heat that will “cook” the specimens. If fire is the heat source, keep the press at safe distance to prevent fire starting on the press. The process of drying may be hastened with the aid of artificial heat like an electric heater. Sometimes it is also possible to exploit the heat from the sun. In this case the presses must be rather small.

Changing the paper is surely a very important step whose importance must not be underestimated. In the first three or four days, a paper change should take place every day. Then one can leave more time between two changes. If the change of paper is neglected, the plants will take more time to loose their water content, besides they could be damaged if the paper stays wet for a few days.

While changing the paper one must try to keep the specimens intact, besides taking care not to mix up the tags or labels with the name and the other information regarding the drying plants. Once a specimen has become dry and stiff, it can be placed into the herbarium.

Step # 7. Mounting of Specimens on Herbarium Sheets:

Once the specimens have been dried, they will have to be mounted on a strong mounting paper sheet to display the specimens and its data in the most clear possible way, and the specimens will be carefully preserved being attached to mounting paper.

Arrangement of Specimen on Mounting Paper:

It is very important that the plants be arranged properly so that one can immediately see all the main characters of any particular species. The best manner to place the plants on the mounting sheets is to align them with the right side of the page (or diagonally if space is required) and to have the heaviest parts and specimens at the bottom (Fig. 4.1e).

The longest specimens can be folded if that can prevent the cutting of the stem into pieces. It is better to leave an empty space at the borders of the mounting sheets.

One can either arrange the specimens (along with the labels and envelopes for small parts) in a regular way from page to page, or stagger the specimens at different positions on each sheet, so that each group of sheets will have a more equally distributed pressure.

The best permanent support is good white or cream cartridge-type paper, in particular 100% rag or chemical wood pulp. The size for mounting paper can range from 42吖 cm. to 45吚 cm. One may even need larger sheets for some bulky specimens. The size of the mounting paper also may depend on the cabinet or box, which will contain the bundle of plants.

The most delicate mounted specimens may be covered with a protective sheet of translucent paper, which must be rather strong and easy to fold. This paper can also be used to cover only parts of plants, such as fragile petals (Fig. 4. 1f).

Small Envelopes:

Small paper envelopes can contain particular portions (e.g. seeds) or very small plants. When these envelopes are folded and glued to the sheet, it should be possible to open them flat and close them without clips. Besides they must securely hold their contents (Fig. 4.1g).

There are different ways to mount the specimens to the herbarium sheets:

In this method, the specimens are strapped with linen or cotton thread, that are knotted on the reverse side of the sheet, where it is better to add some gummed paper to avoid contact with underlying specimens (Fig. 4.1h). Also gummed linen tape, like the one used by bookbinders, can be used.

It must be placed where the specimens have greater strength, avoiding covering delicate details such as flowers. This method, allows to remove, and examine the specimen every time needed, but will allow a certain degree of movement, which can cause some trouble.

If glue is chosen to mount the specimens, water-based woodworking adhesive or library pastes or latex adhesives must be used, which must be applied quickly, taking care of not using an excessive amount. One can employ a brush or a nozzle applicator, otherwise the specimen (especially if it is a small one) can be put in contact with a plate full of glue then attached to the sheet.

Glued material should then be left under pressure overnight, covering each sheet with waxed paper and with drying paper. For aquatic plants only latex glue must be used for gluing the specimens, as these plants can take up water from the glue.

Specimens can also be mounted using small paper bands, which fix the plant to the sheet with the help of pins. The strip is placed on the stem (or other crucial parts of the specimen) and the pin joins together the mounting sheet, the stem and the strip, passing below the specimen (Fig. 4.1i). As for strapping, this manner leaves a remarkable freedom of movement for further examination.

Each specimen must have a label on its own sheet. It is advisable to use permanent and water resistant ink (black or blue), otherwise a pencil can be used (medium lead).

The label should include the following:

a. Taxonomic denomination (at least family, genus and species).

In italics or underlined. If there is an intraspecific name it may be included.

Indicate, in caps, the country or place where the plant was found, followed by a colon (:). Then give the location where the plant was found so that, (a) the spot might be found by someone else in distant future, and (b) a person with a generalized road map could find the location again. Avoid such references as “hill near my house” or “front of grandfather’s barn

Try to indicate where i.e. the locality where the plant was found. This can often be done, by noting the type of soil or rock, outcrop, exposure, or general condition where the plant was found. One can amplify this by indicating the associated plants. In some cases, elevation is useful. Likewise, a general statement about the abundance of the plant may be helpful, especially to those in the future studying plant distributions.

e. Descriptive Information:

Information about the plant that either cannot be seen or might be lost in the future should be recorded on the label. Some taxonomists add local common names if they learn them and local uses. Observations are often useful and can help future scientists better understand the plant.

f. Collector(s) Name(s) and Number:

All person involved with the collecting of specimens should be recorded within reason. Mostly the names of two to five additional collectors are recorded on labels. However, the primary collector’s name appears first and the collector’s collection number is reported.

The date the collection was made should be recorded on the label. One should avoid using 08/09/94 as in the United States this usually means 9 Aug., 1994 while in Europe this would mean 8 Sep., 1994. The taxonomic community has largely adopted the mode of giving the day of the month first, followed by month (first three letters if abbreviated and then without a period) and finally the full year (1994, not 94).

Step # 8. Herbarium Organization:

The mounted specimens must be placed in bundles, which could be kept together with the help of strings or straps. Besides it is better to have cardboard or millboard supports at top and bottom of the bundles, to gain further steadiness (Fig. 4j). Each bundle must have its own label so that one will be immediately able to recognize the contents of each particular group of specimens.

Depending on the number of plants in each bundle and on the criteria chosen when dividing the collected plants into groups, one may write down the geographic origin or the taxonomic level (family, genus, etc.) or whatever identifies every particular bundle. The mounted specimens are stored systematically in special wooden or steel cabinets with pigeon holes also.

The herbarium must follow a certain arrangement, which will give some logical and scientific order to the collection. There are various systematic arrangements that can be followed. In most of the Indian herbaria the specimens are arranged according to Bentham and Hooker’s system of classification.

One can also choose to divide the specimens by their families (or even genus) alphabetically, or else one can group them geographically. These collections of specimens should then be kept inside boxes or cabinets, which should remain tightly closed and dust-proof.

The best places one can choose for the herbarium should be safe from the danger of fire, floods and other accidents. The temperature should be around 20° C and the humidity should not exceed 60%, in order to prevent fungal infections. Adequate ventilation is required, especially if the herbarium itself has a high concentration of insecticide or fungicide.

A dry room is the best to avoid proliferation of insects and consequent damage. Naphthalene and Para dichlorobenzene (PDB) are chemical repellents often used for preventing infestation. They are however very effective only at high concentrations, which increases the risks for human health.

Other products, which have been used in large herbaria are, mercuric chloride, cresol and LPCP, but they are complicated to use, and the results can be dangerous to human health too.


Deciphering a Weed. Genomic Sequencing of Arabidopsis

By the end of 2000, the genomic sequence of the model plant, Arabidopsis, will be completed, annotated, and released. Although the hype over the draft of the human genome sequence may overshadow the significance of this lowly weed, its importance for the future food security of the world's population may have equal weight for human health with the actual catalog of human genes. In recent months the popular media have enthusiastically reported protests around the world against the use of genetically modified organisms, especially plants. While farmers have been breeding, and thereby modifying, agricultural crops for millennia, protesters feel that the use of recombinant DNA for changing the characteristics of plants is inherently dangerous. Nevertheless, the entire complement of Arabidopsis genes will define the first member of the “other” multicellular biological kingdom and along with the emerging rice genome it will facilitate even more precise manipulations of crop species to achieve targeted goals. In addition, this will be the most accurate and most complete sequence of a higher eukaryotic genome in existence and it will probably retain that status for some years to come. At this historic juncture it is well worth a quick review and acknowledgment of the process and the people whose efforts have made this achievement possible.

It was just over a decade ago that the Arabidopsis Multinational Science Steering Committee, a small group of forward-thinking Arabidopsis researchers, decided that the most valuable goal for the advancement of plant science was the determination of the entire sequence of the approximately 130-Mb Arabidopsis genome. With a target completion date of 2004, new sources of funding and scientists interested in undertaking such a large effort had to be identified without detracting from other aspects of basic plant biology research. Early projects focused on identifying expressed genes through single-pass sequencing of cDNA clones Tom Newman and colleagues at Michigan State University ( Newman et al., 1994) and a group of investigators in France ( Höfte et al., 1993) produced a large number of expressed sequence tags (EST) that were collected in the database dbEST ( Boguski et al., 1993). Preparations for genomic sequencing in the early 1990s in Europe and the U.S. were directed toward establishing the optimal molecular resources such as appropriate large-insert libraries and physical maps of the individual chromosomes. Genomic libraries of Arabidopsis DNA were constructed in cosmids ( Hauge and Goodman, 1992) and yeast artificial chromosomes ( Matallana, et al., 1992 Schmidt et al., 1995 Zachgo et al., 1996), and much effort went into restriction mapping and hybridization of these clones to localize known genetic markers and to generate a sequence-ready map. However, it became apparent that there were difficulties inherent in these vectors, such as clone instability and incomplete representation of the genome, which would limit their utility as substrates in a full genome sequencing project. In the mid-1990s, bacterial artificial chromosomes (BACs Shizuya et al., 1992) were emerging as the vectors of choice for this type of project due to their reasonably large insert size (approximately 70–200 kb), low copy number in Escherichia coli, and apparent insert stability. Rod Wing's group, then at Texas A&M University, and Thomas Altmann's group at the Max-Planck-Institut für Molekulare Pflanzenphysiologie in Golm, Germany constructed complementary BAC libraries using different restriction enzymes. These two libraries became the mainstay of the sequencing projects in Europe and the U.S. in addition, the Japanese developed libraries to support their sequencing efforts in a P1 vector and in a modified BAC vector that could be used inAgrobacterium-mediated plant transformation.

The Europeans were the first to organize a sequencing consortium and obtain funding for a pilot genomic sequencing effort. Led by Mike Bevan at the John Innes Centre in Norwich, 18 European laboratories formed “European Scientists Sequencing Arabidopsis” to sequence approximately 1.9 Mb on chromosome 4. In December 1995, the Kasuza DNA Research Institute in Japan initiated their Arabidopsis sequencing efforts, focusing on chromosome 5. Soon after, in 1996 three U.S. funding agencies, the Department of Energy, Department of Agriculture, and the National Science Foundation as the lead agency requested proposals and funded three pilot sequencing projects in the U.S. Arabidopsis sequencing at The Institute for Genomic Research (TIGR) focused initially on chromosome 2 and was directed by Steve Rounsley and Craig Venter. The second U.S. effort, a consortium of researchers at Cold Spring Harbor Laboratory led by Dick McCombie at the Genome Sequencing Center of Washington University School of Medicine in St. Louis headed by Rick Wilson, and at Applied Biosystems Inc. with Ellson Chen, focused on the top arm of chromosome 4. The third U.S. project, concentrating on chromosome 1, was directed by the SPP Consortium composed of the Stanford DNA Sequencing and Technology Center under Ron Davis and Nancy Federspiel, Joe Ecker's group at the University of Pennsylvania, and Sakis Theologis' group at the Plant Gene Expression Center/UC-Berkeley. In the summer of 1996, representatives of all the international sequencing groups met at the first AGI (Arabidopsis Genome Initiative) meeting and established guidelines for sequencing standards and accuracy, data release, and resolution of conflicts. The AGI has played an essential role for the last 5 years in coordinating the international efforts, monitoring progress, allocating regions of the genome to new participants, and redistributing areas to utilize excess sequencing capacity. Subsequent rounds of funding in the U.S. and Europe increased the rate of progress and included an additional European consortium led by the French genome center Genoscope under Marcel Salanoubat and Francis Quetier, focusing on chromosome 3. The combined efforts of all the groups has led to the completion of the Arabidopsis genome 4 years ahead of the original schedule!

Considering that over 40 laboratories have participated in this enormous undertaking, it is interesting to compare the different strategies that were used (or not used) to define the genomic structure of Arabidopsis. These strategies are variations along a gradient from fully random sample sequencing to highly directed localized sequencing. Whole genome shotgun sequencing (in which total genomic DNA is sheared into small pieces, cloned, and sequenced) was proposed as one component of the effort by the SPP Consortium because the resulting random sequences would tag nearly every gene in the genome in the first phase of the project. Directed sequencing, in contrast, produces highly accurate sequence in discrete areas of individual chromosomes, whereas other chromosomal areas remain unknown until late in the process. At the first AGI meeting there was vigorous debate among the representatives over the whole genome shotgun strategy and it was decided by majority vote not to support it due to concerns over how the data could be utilized and incorporated into the final, highly accurate product. Five years later this strategy has become much more accepted in the biological community as an efficient way of surveying a new genome in the initial stages of analysis.

Participants in the AGI then utilized the more directed approaches with BAC or other large-insert clones that were mapped to specific chromosomes as substrates for all the sequencing efforts. European Scientists Sequencing Arabidopsis, composed of a large number of laboratories with varying sequencing capacities, chose early on to invest in a large mapping effort to establish an overlapping set of clones distributed along their chosen chromosomal locations. Once the list of clones was defined, individual clones were allocated to the different participating laboratories for sequencing, and each laboratory could operate independently of the others on its own set of clones. Using this approach, the first large contiguous stretch of Arabidopsis genomic sequence was completed and it was revealed that the predicted gene density in Arabidopsis is quite high, averaging 1 gene/5 kb (Bevan et al., 1998). An alternative approach was used by many of the other sequencing groups, which required less initial effort on mapping clones this strategy instead required a database of the end sequences of all the available BAC clones. To initiate the process, “seed” BACs were mapped to widely distributed sites along a chromosome and then completely sequenced. The sequence of each seed BAC was then compared with the end-sequence database to identify the BAC clones that overlapped each end by a minimum amount. These BACs were in turn sequenced completely to extend the region of contiguous sequence and the process was repeated until the “contigs” merged to form the entire sequence of a chromosomal arm (centromeric repeats are difficult to sequence and require specialized strategies). This approach led to the completion of the sequence of chromosome 2 ( Lin et al., 1999) and the mapping strategy resulted in the completion of the sequence of chromosome 4 ( Mayer et al., 1999).

Although most sequencing groups relied heavily on manual labor and, later in the project, some commercial automation for sample preparation, the SPP Consortium used the Arabidopsis sequencing project as the testbed for new robotic instrumentation developed at Stanford to reduce the cost and increase the throughput for sequencing ( Marziali et al., 1997). The AGI agreed to follow the so-called “Bermuda standards” for sequence accuracy established by the Human Genome Project so that the resulting final product should have less than one error per 10,000 bases. However, adhering to the Bermuda standards for immediate data release to GenBank proved to be more problematic for some AGI groups due to their sources of funding and other internal issues. As a result, public release of sequence data ranged from depositing rough draft sequence in GenBank within 24 h of assembly to posting of sequence data on individual web sites, to releasing to GenBank only after finishing to high quality and annotation. This was a continuing source of discussion and negotiation among AGI members throughout the project, especially in the latter stages when re-allocation of clones required data exchange to confirm overlaps and fill gaps in the sequence. Publication of the sequence of the remaining three chromosomes, as well as a discussion of the structure and content of the entire genome, is scheduled for the end of 2000 and will ensure that all AGI sequence data is in the public domain (The Arabidopsis Genome Initiative, in press).

The accumulation of approximately 130 million pieces of Arabidopsis sequence in the database certainly does not in and of itself provide the key to understanding how this model plant works or how to modify economically important crop species for improvement in nutrition, response to stress, and other traits required for long-term agricultural sustainability. It is analogous to now having a book published in a foreign language, divided into five chapters (for the five chromosomes), but having no punctuation to separate the words and sentences and no dictionary for translation. Annotation of the sequence, or defining the interesting features such as genes, repetitive sequences, regulatory regions, etc., will initiate the process of producing a Rosetta stone for the plant genome. Members of the AGI have all been responsible for annotating the clones that were sequenced in the individual groups, and diverse methods have been used to provide these gene labels along the genomic sequence. In general, sequence matches with the EST database, with the non-redundant protein sequence database, and results of gene prediction programs are the bases of annotation.


Weed / Wildflower Identification Guide

This is a guide to some common "weeds" / wildflowers in the average north London garden. I took the first set of photos August 2010 and have been adding to them on and off ever since. All photos were taken myself unless otherwise noted.

I don't know exactly why I like knowing the names of the plants I find. It doesn't help control them but maybe it makes me feel more in control and looking at these plants has made me appreciate them as wildflowers. Please don't ever use pesticides. I never have and never will. Things I really don't want, such as dock, I dig up. But anything that is useful to bees, I think we have to try to live with.

The unknown plants are at the bottom of the page. I've moved the seaside plants to their own page and the saltmarsh plants are on their own page. I have also made a separate page with rosettes as so many plants start as a rosette. There are also pages about Hawkweeds, Hawkbeards and Hawkbits, Japanese Knotweed, and Lamiaceae (mint, nepeta, deadnettle, etc) as I had so many similar flowers I wanted to compare.The following are in alphabetical order.

In order to make this information more accessible, I have listed the contents below and am working on adding clickable links to the specific weed. You can still just scroll through and look at the photos (beginning after the list) if you're not sure what you're looking for. (to be added: perennial sow thistle, sun spurge)

Common Name Latin Name
Alexanders Smyrnium olusatrum
Alfalfa Medicago sativa
Annual Mercury Mercurialis annua
Granny's bonnet /Columbine Aquilegia
Arum Lily/ lords-and-ladies Arum maculatum
Autumn Hawkbit Scorzoneroides autumnalis
Beaked Hawk's-Beard Crepis vesicaria
Betony Stachys officinalis
Morning Glory Ipomoea
Bindweed Calystegia sepium
Black Bryony/Black Bindweed Dioscorea communis
Black Bindweed/Wild Buckwheat Fallopia convolvulus
Black Horehound Ballota nigra
Black Medick Medicago lupulina
Bluebell Hyacinthoides non-scripta
Bramble Rubus
Bristly Ox-tongue Helminthotheca echioides
Buddleja
Bugle Ajuga reptans
Butterbur Petasites
Creeping Bellflower Campanula poscharskyana
Creeping Cinquefoil Potentilla reptans
Caper Spurge Euphorbia lathyris
Cat’s Ear Hypochaeris radicata
Catnip Nepeta cataria
Celandine, lesser and greater Chelidonium majus, Ficaria verna
Celery-leaved Crowfoot Ranunculus sceleratus
Cherry Laurel Prunus laurocerasus
Chickweed Stellaria media
Mouse-ear Chickweed Cerastium fontanum
Water Chickweed Myosoton aquaticum
Chicory Cichorium intybus
Yellow Suckling Clover/Lesser Trefoil/Lesser Hop Trefoil Trifolium dubium
Cockspur / Barnyard Grass Echinochloa crus-galli
Coltsfoot Tussilago farfara
Comfrey Symphytum officinale
Common Bird's-foot Trefoil Lotus corniculatus
Common Daisy / Lawn Daisy Bellis perennis
Common Field-Speedwell Veronica persica
Common Fleabane Pulicaria dysenterica
Common Knotgrass Polygonum aviculare
Common Orache Atriplex patula
Common Toadflax Linaria vulgaris
Corn Chamomile Anthemis arvensis
Corn Marigold Glebionis segetum
Yellow Fumitory Corydalis Lutea
Milkflower Cotoneaster Cotoneaster Lacteus
Creeping Buttercup Ranunculus repens
Creeping Oxalis, inc purple-leaved Oxalis corniculata
Cut-leaved Geranium Geranium dissectum
Dandelion Taraxacum officinale
Dead-nettle Lamium maculatum, Lamium purpureum
Broad-leaved Dock Rumex obtusifolius
Enchanters Nightshade Circaea lutetiana
Evening Primrose Oenothera biennis
Fat hen Chenopodium album
Feverfew Tanacetum parthenium
Field Scabious Knautia arvensis
Field Bindweed Convolvulus arvensis
Flixweed Descurainia sophia
Fool's Parsley Aethusa cynapium
Forget-me-not Myosotis
Fox-and-cubs Pilosella aurantiaca
Foxglove Digitalis
Fringecups Tellima grandiflora
Gallant Soldier Galinsoga parviflora Cav.
Garlic Mustard Alliaria petiolata
Geranium
Dove's-foot Crane's-bill/ Dovesfoot Geranium Geranium Molle
Small-flowered Crane's-bill Geranium pusillum
Geranium Rotundifolium Geranium Rotundifolium
see also Herb Robert
see also Cut-Leaved Geranium
Gipsywort/Gypsywort Lycopus europaeus
Goat's Rue Galega officianlis
Goldilocks Buttercup Ranunculus auricomus
Goosegrass / Cleavers Galium aparine
Goosegrass / Indian Goosegrass / Wiregrass Eleusine indica
Great Burnet Sanguisorba officinalis
Great Water Dock Rumex hydrolapathum
Greater Knapweed Centaurea scabiosa
Green Alkanet Pentaglottis sempervirens
Couch Grass Elymus repens .
Green Spleenwort Asplenium viride
Ground Elder Aegopodium podagraria
Groundsel Senecio vulgaris
Hart's Tongue Fern Asplenium scolopendrium
Hairy Bittercress Cardamine hirsuta
Hawk's Beard Crepis
Hawkweed Ox-tongue Picris hieracioides
Hedge Mustard Sisymbrium officinale
Hedge Woundwort (also in South Coast) Stachys sylvatica
Hemlock Conium maculatum
Hemp-agrimony Eupatorium cannabinum
Herb Robert Geranium robertianum
Common Hogweed Heracleum sphondylium
Honesty Lunaria
Horsetail Equisetum arvenses
Horseweed Conyza canadensis
Stinking Iris, Stinking Gladwin Iris foetidissima
Ivy Hedera
Ivy-Leaved Speedwell Veronica hederifolia
Ivy-Leaved Toadflax Cymbalaria muralis
Japanese Knotweed, see separate page Fallopia japonica
Joe Pye Weed Eutrochium purpureum
Lamb's Ear Stachys byzantina
Lemon Balm Melissa officinalis
Lesser Burdock Arctium minus
Lesser Knapweed Centaurea nigra
London Bur-Marigold Bidens Connata
Liverwort Marchantiophyta
Mallow Malva sylvestris
Sycamore Maple Acer pseudoplatanus
Meadow Buttercup Ranunculus acris
Meadowsweet Filipendula ulmaria
Melilot
Yellow Melilot Melilotus officinalis
White Melilot Melilotus albus
Milk Thistle see Plant Identification Silybum marianum
Michaelmas Daisy Aster Amellus
Mugwort Artemisia vulgaris
Musk Mallow Malva moschata
Black Nightshade Solanum nigrum
Woody Nightshade/Bittersweet Solanum dulcamara
Narrow-leaved Ragwort Senecio inaequidens
Nipplewort Lapsana communis
Old Man's Beard Clematis vitalba
Oxalis Oxalis latifolia
Pink Woodsorrel Oxalis debilis
Iron Cross Oxalis tetraphylla
Ox-eye Daisy Leucanthemum vulgare
Oxford Ragwort Senecio squalidus
Pale Smartweed/Pale Persicaria Persicaria lapathifolia
Spotted Persicaria Persicaria maculosa
Pellitory-of-the Wall Parietaria judaica
Upright Pellitory Parietaria officinalis
Pendulous Sedge Carex pendula
Petty Spurge Euphorbia peplus
Phacelia tanacetifolia Phacelia tanacetifolia
Pheasant Berry / Himalayan Honeysuckle Leycesteria formosa
Pigweed Amaranthus palmeri
Pineapple Weed Matricaria discoidea
Pink-Sorrel Oxalis articulata
Plaintain Plantago
Poppy, Atlas Papaver atlanticum
Poppy, Field / Corn / Red Papaver rhoeas
Poppy, Opium Papaver somniferum
Prickly Lettuce Lactuca serriola
Prickly Sow Thistle Sonchus asper
Purple Loosestrife Lythrum salicaria
Ragwort/Tansy Ragwort Senecio Jacobaea
Red Campion Silene dioica
Red Clover Trifolium pratense
Red Valerian see ID South Coast Centranthus ruber
Ribwort Plantain Plantago lanceolata
Rocket Sisymbrium
Rush, Soft Rush Juncus Effusus
Salad Burnet Sanguisorba minor
Figwort ?? Scrophularia grandiflora
Salsify Tragopogon porrifolius
Stonecrop Sedum Kamtschaticum
Sheep's Sorrel Rumex acetosella
Shepherd's Purse Capsella bursa-pastoris
Silver Birch Betula pendula
Sisymbrium - a rocket, not sure which
Small-flowered Mallow Malva parviflora
Small Nettle Urtica arens
Smooth sow thistle Sonchus oleraceus
Smooth Hawk's-Beard Crepis capillaris
Soapwort Saponaria officinalis
Spiderwort tradescantia
Spotted Medick Medicago arabica
Spotted Spurge Euphorbia maculata
St John's Wort Hypericum perforatum
Stinging Nettles Urtica dioica
Storks-bill Erodium cicutarium
Wild/Alpine/Woodland Strawberry Fragaria vesca
Sweet Rocket Hesperis matronalis
Swine Cress Lepidium coronopus
Tall Flatsedge Cyperus eragrostis
Tansy Tanacetum vulgare
Teasel Dipsacus fullonum
Spear Thistle Cirsium vulgare
Creeping Thistle Cirsium arvense
Three-Cornered Leek Allium triquetrum
Tree of Heaven Ailanthus altissima
Tutsan Hypericum androsaemum
Valerian Centranthus
Great Mullein Verbascum thapsus
Vetch Vicia
Violet Viola odorata
Viper's Bugloss Echium vulgare
Wall Germander Teucrium chamaedrys
Wall Lettuce Lactuca muralis
Wall Speedwell Veronica arvensis
Water Figwort Scrophularia umbrosa
Water Mint Mentha aquatica
White Campion Silene latifolia
White Clover Trifolium repens
White Deadnettle Lamium album
White Stonecrop Sedum album
Wild Angelica Angelica sylvestris
Wild Buckwheat Fallopia convolvulus
Wild Cabbage Brassica oleracea
Wild Garlic / Ramsons Allium ursinum
Wild lettuce Lactuca virosa
Wild Mignonette Reseda lutea
Willow Salix
Willowherbs:
Broad-leaved Willowherb Epilobium montanum
Short fruited Willowherb Epilobium obscurum
Great Hairy Willowherb Epilobium hirsutum
Rosebay Willowherb Chamaenerion angustifolium
Wood Avens Geum urbanum
Yarrow Achillea millefolium
Unknowns

Alexanders ( Smyrnium olusatrum)

I mistakenly had this as wild parsnip but a friend advised it was Alexanders, unlike many of the umbellifers this has yellow flowers, I saw this along Regents Canal, April 2017. (black horehound on the left)

February 2019 some Alexanders along the canal in the same place, just starting, no tall stems emerging yet (aucuba behind)

close-up of the Alexanders leaves

Alfalfa (Medicago sativa)

Thanks to Michael for identifying this (via FB). I saw this along the Regent's Canal near King's Cross.

The following 3 images are all Annual Mercury. Last year I had it all over my front garden, as did my neighbour but after I weeded my garden and her garden well it didn't bloom and set seed so have much less this summer. Annual, easy to pull out.

I include it to help those that may find it growing from self-seeding. Sometimes they get invasive and are pulled up as weeds. I like them because they bloom early before other plants have started. Annual, can be difficult to pull out - quite strong roots. Various coloured flowers.

Here are some aquilegia in bloom.

To the right of the aquilegia is a stachys byzantina, or lambs ear which self-seeds like mad so you may find it springing up like a weed in your garden.

aquilegia seedling, they have these rosettes of leaves which unfurl as they grow - very attractive

aquilegia with powdery mildew which they seem prone to

Arum lily / lords-and-ladies / cuckoo-pint (Arum maculatum)

I saw these in the walled car park round the corner from me on 2-9-2017 so everything is gone but the berries and a couple of lone leaves. I see lots of petty spurge amongst them and corydalis lutea to the left. I'll have to go back in the spring and take more pics.

Autumn Hawkbit ( Scorzoneroides autumnalis)

this example is much smaller than some of the yellow composites, these were only about 12 cm tall, seen August 19th southeast London

Betony (Stachy officinalis)

I saw this Sept 12th in the "wild garden" at Ham House, Surrey.

This is Morning Glory. I include it to distinguish it from bindweed which follows. They are very similar. (to the right are the Honesty seed pods)

Bindweed (see also field bindweed), white flowers similar to morning glory. Easy to pull out at ground level but must be untangled from the plant(s) it has twisted around.

It can be quite long as it tangles around something, even itself. The flowers were 5.5 to 6 cm long on this one.

closer view of the leaves

"Black Bindweed" can refer to tuberous Black Bryony or the annual Wild Buckwheat, each listed below. (thanks to Jacqui who explained they were 2 different plants)

Black Bryony/Black Bindweed (Dioscorea communis)

Thank you to Freda and Les who alerted me to this and provided the photos. They have read that the berries and tubers are both poisonous so beware.

a close-up of the heart-shaped leaf

Sept 2018, I have finally seen black bryony myself, at RSPB Fowlmere in Cambridgeshire. It was after flowering when it had red berries.

Black Bindweed/Wild Buckwheat (Fallopia convolvulus)

I am sure that this came from bird seed (see above Bird Seed Weeds).

Nov 2015 I had a few self-seeding, as of April 2016 these appear to have died over winter but I will keep and eye on those pots and see if they return and hope to see flowers if they do.

May 2016 and the wild buckwheat is back.

I potted it up and it's already produced some buds a few weeks later.

a close-up of the buds a few days later

a couple days later and the flowers are in bloom

Going back to last year (10-2015), I now know that these seedlings were wild buckwheat.

I pulled up one (slightly larger about 10 cm tall) from this area recently (7-2016).

August 2018 I saw this along the Regent's Canal near me and wondering if it's black bindweed / wild buckwheat.

Black Horehound (Ballota nigra)

I saw this along the canal 17-6-2018, much larger and more flowers than the previous one below.

I wanted to clearly show the stem with the whorls.

I saw this along the Regents Canal May 2017. It does look similar to deadnettle which I have loads of in my garden but haven't had this.

I wasn't sure what it was but the pink flowers, on some plants further along the canal, made it identifiable.

Black Medick (Medicago lupulina)

This (I think) was in a mix of seeds of Wildflowers of Ireland my neighbour brought back from a trip there a few years ago. I planted the seeds in pots which have been back and forth between our patios and didn't really keep track. This self-seeded between the paving stones on her patio recently but I'm not really sure when they started. It's only in hindsight I realise where they came from. This is actually quite small, I found it difficult to take photos in focus, this one shows at least the bit at the end of the leaf that sticks out, will try again to take some more photos.

black medick is actually very small, here it is in situ

These may be nice in a wood but in my garden they are very annoying. They form large clumps that prevent other plants from growing. They are perennials that grow from bulbs and must be dug out. I try to do that whenever I find them. This photo was taken after this bluebell finished blooming. The stem of spent flowers is on the left.

bluebell flowers end of March (following 2 photos)

when you have flowers the bluebells are easy to identify but if they haven't bloomed yet, as those below, the leaves have a ridge down the back unlike hyacinth leaves which are smooth making them easy to identify (thank you to Barbara for this info - some of us really don't want bluebells in the garden)

I wasn't sure if these were bluebells or pendulous sedge, or indeed something else. So I thought I would dig them up to be sure.

They are bluebells! with those white bulbs underground.

Then I had a horrific thought. What if all these are bluebells as well. I sort've thought they might be hyacinths - but the hyacinths are already in bloom whereas these are all leaves. I decided to "go for it" and dig them up as well (this is my main flower bed in the sun, above is a shady less important part of the garden).

They are also bluebells, with the white bulbous roots.

Here's a bluebell with a flower coming into bloom

This is one that got away! I've been weeding them out like mad but missed this one which has gotten to be 46 cm high.

At the bottom of the stem is a new flower emerging.

Bluebells do come in different colours, white on the far left, then pink, then shades of purple and blue.

Perennial with tough spreading roots which must be dug out and even then difficult to get all of it as it spreads so far. There are over 400 types of bramble in the UK (according to one of my wildflower books) so it makes sense I have a couple of types. The second one has finally bloomed and produced berries (it can be so difficult to ignore weeds waiting for them to flower, I've been itching to take the secateurs to them).

this is one type, in my front garden, which I think of as the usual wide-spread type of bramble, blackberry-type berries

here's the flower of the 2nd type in my back garden, leaves on the left in the pic below

here are the berries that go with the flower above

the two types of bramble leaves I've noticed

What I think of as the "usual" bramble has lots of fierce thorns (top stem), the other variety is tame in comparison with quite mild thorns which I can touch quite easily

Bristly Oxtongue (Helminthotheca echioides)

I previously only had this on my Identification - South Coast page but I saw it in southeast London yesterday (19-8-2017). Those bracts below the flowers are a distinctive feature as are the blisters on the leaves. One of the plants had very purple-red stems.

those bumps or blisters on the leaves are a distinctive characteristic of bristly oxtongue

Buddleja. It may appear as a weed as it can self-seed and sprout up anywhere. Often seen on buildings, roofs, etc. and can cause damage, eg growing through a brick wall. Must be dug out or just cut above ground level if the roots have spread.

I'm adding another photo of a buddleja I noticed growing in the wall of a house around the corner from me. I guess the seed blew into one of the damp course holes in this wall (I assume that's what they are). This example shows how these buddleja take root anywhere.

This buddleja suddenly appeared in the pot below..

This was taken at the beginning of March. I didn't know what it was at that time. By now (end of May) it's looking very buddleja-like (next pic).

I think these are even smaller buddleja seedlings but I will be able to confirm in a few weeks.

yes those above are buddleja

as soon as those curved middle leaves appear, you can confirm its buddleja

Bugle (Ajuga reptans)

Butterbur (Petasites)

before the flowers appear, it's difficult to tell what the plant is, the round leaves are similar to wild garlic

This campanula (creeping bellflower) has attractive blue flowers but I guess it might get invasive and be considered a weed. I just pulled a clump out that was smothering my lily of the valley. Here's a clump that's taken hold on my path.

Caper Spurge (a type of Euphorbia)

I hadn't seen a caper spurge in my garden for so long at first I didn't realise what it was. I used some home-made compost recently and I suddenly have one appearing. It's younger and fresher than the one above (which was in my first set of weed pics), it got bent so difficult to take a pic in situ so pulled it up.

propped it up to see it from above

I don't usually see the seedheads as I pull out any caper spurge I find before it gets to that point but I saw this locally the other day, growing in a newly planted bed so it grew very well, very quickly.

Catnip (Nepetea cataria)

This white-flowered plant is the herb, grown from seed. I have never seen a Nepeta cataria plant for sale. The related purple-flowered plant, garden catmint (Nepeta faassenii) is widely available from garden centres. I have never seen Nepeta faassenii seed for sale. Cats like both.

The plant in this pot is from seed sown in previous years. The one above I grew from seed this year.

nepeta and dead-nettle can look similar, comparison below, see Lamiaceae page for more comparison among related plants

Cat's Ear (Hypochaeris radicata)

I saw this recently (30-7-2017) in my sister-in-law's garden in northwest London.

May 2019, much nicer examples

This was my original cat's ear pic from 2011 and I'll be honest, I'm not sure if it's cat's ear. At the time I didn't know as much about weeds and wildflowers, especially all these yellow-flowered ones. Looking at it now, I see branched flower stems which cat's ear doesn't have. It's quite mangled so difficult to say but I think it's nipplewort.

greater celandine

more of those very distinctive leaves

Lesser Celandine

I've been looking at weeds for some years (at least since 2010) and have only just seen lesser celandine locally (February 2018) in a park across the road. (common field speedwell leaves top right)

whole lesser celandine plant with flower buds just opening

and suddenly this year (2018), I'm seeing more lesser celandine

I saw this lesser celandine with bronze leaves in new planting at Kings Cross so it's a garden plant, not just a weed. It does have very early flowers.

Celery-leaved Crowfoot / Buttercup (Ranunculus sceleratus)

This was briefly in my Unknowns but thanks again to my Illustrated Book of Wildflowers (yes, a book, still a great resource) I was able to identify this. It really confused me that the leaves top and bottom were different shapes but the book confirmed that. I saw this along Regents Canal initially 30-4-2017 but just had to go back 2-5-2017 to get better pics.

the upper leaves are clearer in this pic (excuse my feet at the bottom)

the lower leaves are clearer in this pic

Cherry Laurel (Prunus laurocerasus)

This acts very much like a weed - it self-seeds and grows too large. This self-seeded in a pot this summer. Finally realised what it was.

close-up of the top leaves

This is in my garden, was here when I moved in, think it self-seeded at some time in the past. It's only advantage is it copes with the shade. Decided to remove it recently before it gets to tree-like proportions. There was a huge tree next door which had to be cut down as it was growing in a flowerbed (will find photo).

After I cut this down, I have it reshooting, the shoots look a bit different from any of the above examples. This is a very persistent tree.

Chickweed (Stellaria media)

I got a few pots from freecycle and wanted to see what would grow, in this case chickweed!

I let it grow and flower so I could take some clear pics

those examples of chickweed above look very lush and green but I saw some on the pavement down the road that were much more sparse, they adapted to their harsher conditions

Chickweed, mouse-ear

in the front with buds at the top (flowering rosemary in the background)

I finally decided I had to pull it out even though the flowers hadn't opened as I really want that rosemary to thrive and not make it compete with a weed. I'm happy with the ID of mouse-ear chickweed for this.

Water Chickweed (Myosoton aquaticum)

I saw this at a nearby park June 2019. I was intrigued as the flowers do look like chickweed but the entire plant is a larger scale and the leaves quite different. Growing quite happily in a dry environment even though it's "water" chickweed.

Chicory ( Cichorium intybus)

Chicory is a flower I love and I have it in my garden, grown from seed but while out walking through the "wild" area of Allen Gardens in Spitalfields (East London) the other day I saw some great examples and realised it's a weed in some circles, definitely a wildflower, so should include it here to help with identification.

this shows the arrangement of the buds along the stem

I wanted to show a close-up of the lower leaves

the upper leaves are quite small in comparison

By that I mean Yellow Suckling Clover/Lesser Trefoil/Lesser Hop Trefoil (Trifolium dubium), or so I've just discovered by googling. I thought it was just Clover! It is all over most of the garden next door which I look after. I never noticed it specifically. I mean I knew there was some clover over there but not this much.

Yellow flowers seem to have taken over the garden next door. I have a lot of creeping buttercup (left, below) at the moment and wanted to compare the flower to that of the clover (right, below) although it's not the clearest pic of the clover. I'll take another but wanted to show what I have in the meantime. I've also dicovered Wall Lettuce and Hedge Mustard recently and of course, there's still the odd smooth sow thistle, nipplewort and coltsfoot, all with yellow flowers.

Cockspur / Barnyard Grass ( Echinochloa crus-galli)

I saw this on the pavement down the road from me by the Sainsbury's on Camden Road.

close-up of that plume at the top

I've been told this is Coltsfoot and possibly invasive. I've not seen it before. It suddenly appeared in the garden next door. On the left is the coltsfoot, on the right a hollyhock and on the left and spreading through underneath is pellitory of the wall.

a couple weeks later, the strikingly coloured stems are more pronounced

It's quite similar to hollyhock, as noted above but worth showing ano photo (below, taken June 2014). Coltsfoot leaf is smooth and shiny, hollyhock is quite textured.

The Coltsfoot is in bloom (March 2014).

The next day the flowers are fully open.

Suddenly the coltsfoot has gone mad - numerous stems and flowers, including dandelion-like ones ready to blow seeds everywhere so I've put it straight into the garden waste bag, not even taking time for a pic before I did it in case any of those seeds got away.- update - of course now I regret being so agressive in its removal - I listened to the negative voice when I should have had more confidence - now I do and I will keep any "weeds" (even thistles) if I want

Comfrey (Symphytum officinale)

a purple wildflower I grew from seed

I saw this one with white flowers in Allen Gardens, Spitalfields (East London) the other day.

Common Bird's-foot Trefoil (Lotus corniculatus)

I guess I've seen this before but it was only yesterday I saw a really nice flower and got some decent photos (outside Pets at Home - a good place for wildflower weeds sometimes).

patches of common bird's-foot trefoil

Common Daisy / Lawn Daisy (Bellis perennis)

Common Field-Speedwell (Veronica persica)

Apologies fellow gardeners, I had this listed as ground-ivy, a recent addition here, but those buds opened today (11-3-2017) and I was able to take a photo and it's definitely not ground-ivy but common field-speedwell, a wildflower I had not encountered before (first noticed it Feb 2017). It's similar to deadnettle so maybe I just didn't take note before. BTW I love those purple flowers and will not be removing it.

bare lengths of stems between groups of leaves

It happens to be growing in the same pot as some deadnettle (on the right) which I originally mistook it for as I have lots of deadnettle everywhere now (I like the small flowers, esp as the bees love them) but here it's easy to see the deadnettle has differently textured leaves which have rounded lobes. The field-speedwell leaves are smooth and toothed. (in the middle is forget-me-not and larger leaves at the top, green alkanet)

Common Fleabane ( Pulicaria dysenterica)

close-up of the flowers with a hoverfly

a bank of common fleabane plants, about 1 to 1.5 m tall

Common Knotgrass

The specimen above looks so small unlike the large clump I noticed the other day.

here is a close-up of that

One of the freecycle pots had common knotgrass which I allowed to grow to see the flowers produced. I didn't realize the "knots" above had the little white flowers but I hadn't taken close-up enough photos. Here are a few I took today:

a wider view of that common knotgrass

Common Orache (atriplex patula)

I saw this growing on the pavement outside my house. I won't pull it out until it flowers.

I saw this common orache along the canal (middle of May 2017). I didn't recognise it at first as I've only previously seen this weed the one time above.

2 weeks later it started to bloom

another clump, in a sunnier position further along the canal, had more flowers

Common Toadflax (Linaria vulgaris)

I think this is usually upright but the plants I saw today (July 2019) were leaning over.

Corn Chamomile (Anthemis arvensis)

definitely a wildflower, not sure how much it's considered a weed, I have it from sowing some wildflower seeds from Ireland a friend gave me

lots of wildflowers have daisy-like flowers - can be confusing, I have ox-eye daisy but I know there are others

Corn Marigold (Glebionis segetum)

Corydalis Lutea (yellow fumitory), grown as a garden plant but I pull it up as a weed as it self-seeds around my garden, including on walls, and I don't really like it. Easy to pull out.

Milkflower Cotoneaster (Cotoneaster lacteus)

This is also on my Plant Identification page but it also behaves very weed-like, eg self-seeding and being a thug and difficult to remove.

I have never seen a flower, or any distinguishing feature, on this shrub in the garden next door but recently I noticed there's one that blooms and produces seeds nearby so that could be where this came from and the seedling in that pot below.

Creeping Buttercup

If left, creeping buttercup soon spreads and gets more and more difficult to pull out. The first one below I tried to pull out with the roots but it just broke off. It was developed enough to have bloomed.

As below you can see these creeping buttercup have multiple stems and they make a very difficult plant to pull out but it's worth trying to get the whole clump.

February 2018, I noticed a small creeping buttercup seedling in a pot and tried to pull it out. Very difficult! seeing how long the roots are I can see why. A very tough weed to dig out from the the garden

Creeping Cinquefoil (Potentilla reptans)

Creeping Oxalis (Oxalis corniculata)

Spreads so can be difficult to get all the parts but if traced can be easily pulled out.

There is a purple-leaved variety of creeping oxalis. I saw this in the road around the corner, end of May 2018.

This Oxalis (below) which I pulled up the other day (Sept 2014) shows 1. how long the roots are which did made it difficult to pull up 2. how runners extend the plant 3. a tiny bud in the middle at the top.

this shows how oxalis puts out runners which helps it spread so much, it loves the cultivated soil in my pots but that also makes it easy to pull out

Cut-leaved Geranium (Geranium dissectum)

Dandelion tough roots that must be dug out - if you really really don't want them but it is useful for bees, especially early when other flowers are not in bloom. I try to leave any in my garden or pots now.

dandelions usually have toothed leaves but some don't (there are loads of different ones of which I'm just learning)

I'm seeing a few different dead-nettles.

Spotted Dead-nettle (Lamium maculatum)

I think this is spotted dead-nettle

I think this is another spotted dead-nettle. Unfortunately I didn't see any flowers on it and it's disappeared from my garden.

Red / Purple Dead-nettle (Lamium purpureum)

this is in a small park across the road, one of the first weeds/wildflowers in bloom, March 2018

comparison of spotted (?) on the left and red on the right, luckily I happened to see them near each other at a local park, clearly different types

Broad-leaved Dock (Rumex obtusifolius)

This is one of the first weed photos I took, before I realised, the photos are much better before the plant is pulled up

This second pic shows a much smaller plant (2 large leaves at the front) and interestingly some other weeds, back, right creeping buttercup, centre right stinging nettle and couch grass at the front and in the middle.

This third image of dockweed (from another neighbour's garden) is of a plant between the other two in size. The tall plant to the right is a teasel. - correction - reviewing this pic and knowing that later there was lesser budock there, I think that's burdock and not dock at all.

This fourth pic of dockweed shows a close-up of the flowers and how differently shaped are the upper leaves on the plant in contrast with the large lower leaves.

small dock plant/seedling, these leaves (below) are between 3 and 6.5 cm, not very recognisable as a dockweed yet

another type of dock? (I think), still researching what kind

this is in the garden next door but I also just saw it on the pavement a few houses down the road

close-up of the flower on the above plant

Enchanters Nightshade (Circaea lutetiana)

Perennial, easy to pull out, see below how all the roots have come out when it's pulled up but if you miss one little bit it can grow a new weed.

If you have to have a weed it's great to have one like this where the entire root comes out.

Here are the earliest seedlings of Enchanter's Nightshade.

Evening Primrose (Oenothera biennis)

I saw this in the protected environment of the walled carpark round the corner from me 2-9-2017

an even earlier plant which I noticed first, then the more developed buds above, then the flowers above that so I realized this is evening primrose, in isolation not sure I would have, well maybe now after I've seen these examples

Fat hen (Chenopodium album)

I found this first one today (8-9-2013) and I don't think I've ever seen a specimen of fat hen with so many flowers and so tall. I didn't measure it but it must be close to 20 cm tall.

yesterday (25-9-2014) I did find an even larger fat hen

August 2017 and I have a new tallest fat hen. I saw this in Allen Gardens, Spitalfields (East London)

earliest seedlings, first week

fat hen after a few weeks

I had so many of these seedlings in a seed tray I thought they were maybe something I'd planted but as they grew they became recognisable. Annual, easy to pull out.

Feverfew (Tanacetum parthenium)

I saw this feverfew locally, 8-2019

I have it in my garden and it self-seeds. I've heard it's repellent to bees so I started to pull it out but it keeps coming back and I don't know about its affect on bees for sure.

Field Bindweed (Convolvulus arvensis)

I did just have this on my South Coast and Downs page but I saw it near to me in London so I'm adding today's (13-6-2018) photo here. I suspect this is from a mix of wildflower seeds.

Field Scabious (Knautia arvensis)

I hope this photograph shows it clearly enough for identification, the leaves at the bottom are amongst a teasel. I planted wildflower seeds for this so not sure how wide-spread in London.

Flixweed ( Descurainia sophia)

Fool's Parsley (Aethusa cynapium)

I saw this at the community garden on Hampstead Rd at the HS2 works January 2019.

Forget-Me-Not, blooms very early in the spring, I guess this is next year's crop. I let them grow until they get invasive and compete with other plants then I pull them out. Easy to pull out.

Here are some forget-me-nots later in the season after they have bloomed. A weed or welcome flower, your choice.

Fox-and-Cubs (Pilosella aurantiaca)

I bought this at the garden centre as a wildflower but some may find it invasive in their garden.

these are new plants the next year that self-seeded from my originals

I grow these from seed but there are always some that sprout up unexpectedly from self-seeding as this one did. They are a wonderful flower but not if they sprout up in the wrong place.

This foxglove self-seeded in my neighbours' brick wall. I love foxgloves but this one is in the wrong, potentially damaging, position.

Fringecups (Tellima grandiflora)

I saw this in a restricted access area near the Regent's Canal so although they aren't in focus I couldn't easily go back and re-take them. I do hope to get back there one day.

Gallant Soldier (Galinsoga parviflora Cav.)

Saw this on the pavement nearby.

a close-up of the above plant

Garlic Mustard (Alliaria petiolata)

A reader asked me about this and suddenly I saw a lot of plants locally (end of April 2017), especially along the Regent's Canal. I've never seen it in my garden.

the spiky bits are the seed capsules left after the flowers are finished

Reading about it, the first year the garlic mustard starts as a rosette of leaves and then grows taller and blooms in the second year. I went back to the canal and noticed a number of these small plants nearby, not that rosette-like but I still think these are the new first year garlic mustard plants.

Geranium Molle

I saw this off Hampstead Rd, near the railway lines out of Euston. It's in flower so quite identifiable unlike the one below which I saw in the garden next door

I gave up waiting for this to flower, I don't know why, the one I found above is quite pleasant, but I think this is also geranium molle.

Geranium Rotundifolium

I think this is geranium rotundifolium but I only saw it yesterday (14-10-2017) for the first time and I never heard of it before but the flowers do not match the other geranium wildflowers I know. It's also in bloom in October when some resources suggest an earlier finish to flowering but it seems with global warming the usual "rules" are out the window.

Small-flowered Geranium (Geranium pusillum)

I was looking at a weed on the other side of this lamp post when I noticed the small purple flowers on a geranium on the other side - unmistakeable as a geranium with those distinctive leaves. I took photos, of course, and when I researched it, realised it was a different geranium from others I've seen. The flowers were so small I had to get right down to take close-up photos, none of which are that great so will go back and try again but in the meantime I've added the photos I have.

Gipsywort/Gypsywort (Lycopus europaeus)

July 2017 It has been so hot and dry and the canal quite barren. It's finally rained and this gipsywort has sprung up and bloomed.

this was along the canal a few months before, in April, I was hoping to see if it had flowered but it was long gone after the weeks of drought, it wasn't right by the water like the one above, I presume it is gipsywort although it's so different from the fresh bright green example above

Goat's Rue (Galega officianalis)

I saw this along Regent's Canal August 2018. I went back a week later to examine it further but it had been mown, sadly. Just going by these photos I think it is goat's rue although it does look similar to vetch.

Goldilocks Buttercup (Ranunculus auricomus)

January 2019, seen local to me (London NW1), this is quite a tentative identification (if anyone knows different, please lmk) as this is the first time I've seen this, flower is quite small although I didn't measure it (it was bitter cold)

straight narrow leaves aside from a few at the base of the usual buttercup shape

Goosegrass/ Cleavers (Galium aparine)

very early goosegrass seedling

at first I didn't recognise it but as it grew and I touched it and found that dry stickiness, it became clear it's goosegrass

early pic of goosegrass (taken before I realised not to pull the weeds up before I take a pic)

tiny white flowers of the goosegrass, below, buds just visible in the pic above

Goosegrass / Indian Goosegrass / Wiregrass (Eleusine indica)

Great Burnet (Sanguisorba officinalis)

I don't know if that bee was on the great burnet - I didn't even realize a bee was in the photo until I was at my pc.

close-up of the great burnet leaves

Great Water Dock (Rumex hydrolapathum)

I think this must be great water dock, seen August 2018 along Regent's Canal.

Identifying the example above, it has made me review this dock which I had previously identified as sharp dock but I think it must be great water dock as well.

This is along the Regent's Canal, London NW1, August 2017.

Greater Knapweed (Centaurea scabiosa)

I love greater knapweed and bought wildflower seeds to grow it in my garden. I did see it on the South Downs once (see Identification - South Coast).

This is a small greater knapweed plant in March.

Green Alkanet (Pentaglottis sempervirens)

I love Green Alkanet with its beautiful blue flowers in bloom very early in the spring, good for bees when little else is in bloom. Don't worry if it covers the garden (as it does mine in early spring), it dies back before other plants get going. The leaves do have a similarity to foxglove but the alkanet has slightly stinging rough hairs whereas the foxglove is very smooth and soft.

green alkanet seedlings: on the right in the black plastic pot on the left and on the left in the terracotta pot at the bottom of the pic, compare with the textured leaves of the foxgloves: to the right in bottom terracotta pot and in the very small pot bottom right

also in the pots below top right: dandelion along with viola and verbena bonariensis, bottom left pot: forget-me-not in the middle with that distinctive strong line down the middle of the leaf making it identifiable

close-up of the green alkanet seedlings from above, they have that distinctive folded 3rd leaf (and a tiny, tiny oxalis with the long thin root, in the small plastic pot bottom right above)

green alkanet without its distinctive blue flowers

Grass different types

Couch Grass. Spreads but can be pulled out at the base.

This is the couch grass flower

while pulling up this grass which had spread to one of my pots I noticed how red the bases of the clumps were, I never noticed that before, I'm wondering now if it is all couch grass or just a variation or detail I never noticed, will try to find out although it's annoying I'm always happy it's relatively easy to pull out

also couch grass or another grass? this looks quite different from the clumps above but maybe they would turn into that given time?

close-up of one of the spreading roots above

some sort of grass weed, goosegrass? (not to be confused with cleavers), crabgrass? will research further

Green Spleenwort (Asplenium viride)

thanks to Mike (FB) for his help identifying this

Ground Elder. Perennial, must be dug out, including every piece of root which will grow if left. I did have it over half the garden but I don't seem to have any now after digging it out and repeating whenever I see any which is what Bob Flowerdew recommends. Eventually it weakens the plant. It took a few years but it worked.

The photo above is from 2011, one of my earlier weed photos. I had worked hard to remove all the ground elder so was surprised to see a fully formed plant with a spray of flowers beginning of June 2018.

It grew quite tall to reach the sun.

I thought I had completely eradicated ground elder but found a couple little sprouts.

This last pic here shows the ground elder with the roots after I dug it up. I got most of it but some definitely broke off. I'm sure it will come back but I must keep digging it up whenever I see it.

I saw this a few weeks ago and mistook it for horseweed but today (a few weeks later) it was a lot more identifiable. (I did take a pic but it's not as clear as the one above.)

this has me completely confused, it looks similar to groundsel but the leaves are a different shape, ragwort? Oxford ragwort?

and just to confuse things further, a groundsel has self-seeded itself next to this (pulled it out and laid it next to this for comparison) and it is definitely different leaves at the top but similar leaves at the bottom, definitely thinking senecio weeds (groundsel, ragwort, Oxford ragwort, not sure if there are others)

Hart's Tongue Fern

this is one of those plants, does it go on the weed page or plant page? this and the dryopteris fern act very weed-like, this self-seeding in a wall by the Regent's Canal near King's Cross, so I think they can be acknowledged as weeds

I saw this hart's tongue fern in a Regent's Park garden mid-November 2018 so not a weed in this instance.

underside of the hart's tongue fern showing the spores

Hogweed and Hairy Bittercress, below, also see next 2 entries.

The following is hairy bittercress. At first it's quite low-growing, a small clump on the ground (see hogweed pic above) but then the flower stems shoot up as below. Annual, easy to pull out.

The seedling is quite flat on the ground and then suddenly a stem shoots up from the centre.

hairy bittercress seedlings, before the central stem has shot up

and here is the tiniest, tiniest beginning of the hairy bittercress (about 1.2 cm wide)

with the cat just to put it into perspective (it's the seedling on the bottom right)


This is one of the oldest hairy bittercress I've seen. I've just discovered it in a pot end of March 2015. It seems to have survived the winter, which was mild and turned into an established plant - that won't last long!

Having another look at this and the examples I've seen on Hayling Island, and I think it's Hawk's-beard, either beaked or smooth, not absolutely certain so far. In flower May to July, long bare stems rising above base rosette of toothed leaves, multiple branching flower stems from the top part of the stems.

I noticed this mid-July locally (Camden Gardens, north London) after previously only seeing it on the southcoast and putting it on my southcoast identification page.

March 2017, I notice some small plants in the same spot and think they are the new season's growth. I don't know if they are new seedlings or growing from the existing plants. Will keep a watch on how they develop. -update - they did grow and bloom but before I could take a photo they were vandalised, maybe because someone noticed me taking photos and taking an interest in them? That's a discouraging aspect of life in London.

a close-up of the leaves show the prickly edge

Hedge Mustard (Sisymbrium officinale)

I'm surprised I've never seen this in the garden before today (June 13th 2014). I'm seeing this everywhere now. I pulled it up and put it on my front doorstep to take a pic. I think hedge mustard must go in phases. 2014 was a year for hedge mustard and I'm finding 2017 is as well.

It's appeared both in the garden and out, the pavement outside my house.

close-up of the hedge mustard flower

I saw a lot of hedge mustard yesterday (21-4-2017) off a main road and wanted to show some more details of it.

before the longer stem with the flowers appear

close-up of the hedge mustard flowers and buds

seeing all that hedge mustard the other day made me re-consider the plant on the left which I had originally (mistakenly) called smooth sow thistle but I realise it is hedge mustard (prickly sow thistle on the right)

close-up of those textured leaves

and another view of that close-up

Hedge Woundwort (Stachys sylvatica)

I saw this at RSPB Fowlmere (Cambridgeshire) so adding here. Honestly don't know how common it is actually in London. Previously I just had it at South Downs and Coast.

leaves further down the plant

There was a lot of the hedge woundwort at Fowlmere so I was able to see it at all stages. This is one of the small plants.

this is in a park round the corner, very tall weed with white flowers, we saw a few different examples on the Chelsea Fringe Weed Walk

Hemp-agrimony ( Eupatorium cannabinum)

I saw this at RSPB Fowlmere end of September 2018. It is similar to Joe-Pye weed and I'm not absolutely certain of the differences but as hemp-agrimony is a native wildflower in the UK and Joe-Pye weed is native to North America I think hemp-agrimony is a more likely ID for this.

Certainly lots of it, at all stages, mostly fluffy spent flowerheads but also buds and flowers. Firstly, buds.

close-up of the buds with some just starting to open

close-up of the flowers fully open

flowers in full bloom and some starting to wilt

I saw this at Spitalfields Farm (East London) this week (August 2017).

close-up of the flowers, vetch in the background

Herb Robert (Geranium robertianum)

The following 3 photos show Herb Robert. Some people grow it as a garden plant. Personally I can't bear it, especially the smell, and pull it out wherever I find it. Annual, easy to pull out.

And here is herb robert in bloom. Some people like it as a flower. I pull it up as a weed wherever I find it.

Herb Robert seedling, the seed leaves precede the very distinctive leaves

also oxalis and teasel in this pot

The following are hogweed. I collected the seed as a wildflower but not sure it's good for a small garden so disposed of it (very small hairy bittercress in the ground to the left of the pots).

This Honesty (Lunaria), larger heart-shaped leaves) is another plant that self-seeds. I let it grow because I like it but some may pull it out. It blooms early with the aquilegia and alkanet before other plants. The dried seedheads can be seen to the right of the morning glory above. Easy to pull out.

I saw this lunaria today (18-1-2014) and thought it would be worth capturing the texture of the leaves and now that I've put the photo here I see how different the texture looks from the one above. Bottom centre here is green alkanet. The one on the right underneath is teasel. Of course, at the top is ivy.

I don't know what makes leaves red like this, will try to find out more.

honesty seed pods, initially green they will turn brown and papery, these "coins" give the plant its other name, the money plant

very small honesty (lunaria) seedlings

a small honesty plant with those distinctive center leaves

another, more developed, honesty plant

Horsetail (Equisetum arvenses)

I saw this at a train station in southwest London, first week of May 2018.

(I also saw some brown dried spikes of horsetail on the South Downs in April 2018, see South Downs and Coast identification page)

Horseweed (Conyza canadensis)

tall annual weed with small white flowers

not all horseweed start with the rosette of leaves, I think it depends when they start growing

this one has been growing the last few weeks in this pot and never had that rosette of notched leaves, about 40 cm tall

there are some buds at the top

Iris foetidissima

This is another self-seeder and it can make rather large clumps. It's useful in shady areas where it's difficult to get things to grow but it can also get invasive and weed-like. Difficult to pull out.

Iris foetidissima seed pods

iris foetidissima seed pods splitting open to reveal those bright orange seeds

Ivy (Hedera)

Ivy can root anywhere. If you try to cut ivy down but don't remove all the branches, they will root into a wall, brickwork, anywhere. Don't think if you cut connection to the roots, you have killed it, you haven't! I found this ivy had rooted into a bag of crushed shells I had for mulching.

types of ivy leaves I have in my garden, I guess there was lots of ivy there when I moved here

I came across this ivy in flower with lots of bees at RSPB Fowlmere last week (end of September 2018) and wanted to know which kind it was. I think it's Irish ivy (Hedera hibernica). It reminded me of my comparison of the ivies I have in my garden and the photo I took of all the leaves back in 2014 (above). Now I need to go back and research which kinds they are.

Ivy-Leaved Speedwell

tiny flowers, matt and hairy whereas the ivy-leaved toadflax below is smooth and shiny

Ivy-Leaved Toadflax

This was taken beginning of April, when the flowers appeared. Smooth and shiny in contrast to the ivy-leaved speedwell above which is hairy.

the reddish buds before the flowers appear, below

Japanese Knotweed (Fallopia japonica)

Joe Pye Weed (Eutrochium purpureum)

Knotgrass, see Common Knotgrass

Lamb's Ear (Stachys byzantina)

I'm putting this on the Weed rather than Plant page as it self-seeds like a weed, as it's doing here in this pot. At first the leaves are quite textured and most unlike the fuzzy leaves to come later.

those supersoft leaves coming from the centre

full-size lamb's ear plant flowering

Lemon Balm (Melissa officinalis)

close-ups of some of the lemon balm flowers, the buds appear quite yellow but after they open the flowers appear white

Lesser Burdock

This suddenly appeared, fully formed, in this clump next door (August 2014). They aren't keen gardeners but I thought I would have noticed! The flowers are very thistle-like but the leaves are completely different.

this entire clump is burdock, I'm not sure if it's lesser or greater burdock

that clump above has long since been cleared and recently (June 2016) the lawn was mown, shortly after that this small plant appeared

I saw these yesterday (21-4-2017) off a nearby main road. I wonder how tall they'll get if left to grow.

this lesser burdock I saw at RSPB Fowlmere in Cambridgeshire end of September 2018

Lesser Knapweed (Centaurea nigra)

I bought this as a "wildflower" at the garden centre (they were on sale so couldn't resist) but some may have this self-seeding in their garden.

close-up of a knapweed flower

London Bur-Marigold (Bidens Connata)

This has been in my Weed Gallery (a few picturesque weed photos) for years as an unknown but I recently came across an ID. I saw this growing in the Regent's Canal near me in Camden Town, northwest London, appropriate as it spread along the Grand Union Canal network, of which the Regent's Canal is part.

Liverwort (Marchantiophyta)

This is a moss-like weed that has appeared in some seed trays.

from that one small "sprout", the liverwort has spread quite a lot in my pots but it doesn't seem to cause much of a problem, recently I've noticed these upright growths

I read somewhere recently about this being a weed but I sowed it myself as a wildflower from seed. I took this pic on June 11th and it's not in bloom yet. (a comparison with wood avens is below in the wood avens entry)

beginning of July and I see my first mallow flower

Here is a more established plant (with lots of flowers).

This is a maple seedling. For some reason I have masses of them this spring (2012). I wasn't sure what they were, as I never noticed them before, until I found this one with the seedpod (whirligig) still attached.

here's another whirligig with the seedling just emerging

This is it after I've pulled it out of the ground which gets more difficult as they get larger. I just about managed this one as the ground was wet.

Meadow Buttercup (Ranunculus acris)

Meadowsweet ( Filipendula ulmaria)

close-up of the meadowsweet flowers

close-up of the meadowsweet leaves

Yellow Melilot (Melilotus officinalis)

I saw this beginning of July 2019, near the railway line, along from Camden Road station where I'd originally seen melilot from the platform but couldn't get a very good view.

a view of the wider environment with the railway line in the background

White Melilot (Melilotus albus)

I saw this on the edge of Epping Forest 19-7-2019

Milk Thistle (see Plant Identification page)

Michaelmas Daisy (Aster Amellus)

August 2017, this year the flowers are earlier because of the hot weather we've had

the michaelmas daisies are the plants with the long thin leaves amongst the chinese lanterns

Thank you to reader Digeroo who has identified this as mugwort There were two of these so I left one and pulled out one. I'd like to take another pic of it when it blooms.

another one sprang up on the other side of the garden next door, the bright blue flowers are green alkanet

mugwort flower, I don't know if this is fully in bloom or if each of the small "buds" are going to open, I sure want to catch any seeds before they're let loose so I will keep an eye on these

Musk Mallow ( Malva moschata)

I had this misidentified as a cut-leaved geranium as the leaves as so geranium-like but I realised the flower just wasn't geranium but musk mallow.

Nightshade, Black

white flowers and green and black (bottom left) berries, I saw this along the Regent's Canal

I saw this in Bloomsbury this week (15-8-2016), very distinctive leaf shape as above

Nightshade, Woody also known as Bittersweet

Thank you to Suzanne who originally identified Woody Nightshade. I've taken a better pic of one I saw round the corner.

its distinctive purple and yellow flowers (that green plant wrapping around it is something else, think maybe honeysuckle)

Narrow-leaved Ragwort ( Senecio inaequidens)

Nipplewort ( Lapsana communis) , early July I see lots in flower (see example below), annual

Here's a nipplewort seedling mid-April. In my efforts to show the earliest seedlings I wanted to show this. If we can identify these very early seedlings we can weed them out before they get established, but most importantly before they set seed.

nipplewort seedling as a rosette of leaves, I think, like horseweed, nipplewort starts with a rosette of leaves depending on when it starts growing

this nipplewort seedling started off as a rosette flat on the ground (end of January/beginning of February 2017) and just started to grow upwards before I took this pic (on Feb 18th)

close-up of the nipplewort flower

At first I thought this might be Wall Lettuce, esp as I couldn't see the bottom of the plant (the flowers are very similar). I had to pull it up, to both identify it and take a photo showing it all. It became clear it's Nipplewort, with those distinctive notched leaves at the bottom. I don't usually let Nipplewort grow and see it this tall but this one got away.

Old Man's Beard (Clematis vitalba)

I saw this near the entrance to Camley Street Natural Park (Victorian water tower in the background which was moved from St Pancras to near St Pancras Lock, the other side of the tower). I also see this clematis self-seeded in the garden next door to me but it's not nearly as developed as this and it hasn't bloomed this year.

seedheads not quite "beardy" yet, one in the pic above is getting that way

Old Man's Beard self-seeded in the patio next door April 2018

more identifiable June 2018

September 2018, not developed enough to bloom that year

huge shrub up the road with fluffy seed heads

Orache, see Common Orache

checking which one this is

I usually pull the oxalis up whenever I see it but one plant bloomed before I noticed it and then I realised I didn't have a pic here of the flower so I've taken one. I just noticed the yellow buds on the plant above.


thank you to Tom for alerting me to oxalis growing from little bulbs left in the soil under the surface

Oct 2018, I took this out of a pot where it shouldn't have been. (Oxalis latifolia? or debilis?) I'm not absolutely certain. It has a large bulb and bulbils around the top. On the right is a larger bulbil that obviously developed to a larger size on its own. All the leaves are from stems growing directly from the ground unlike other oxalis which may have branching stems.

the bulbils easily broke off when I dug it up

close-up of the bulb and bulbils

After I was trying to identify this I realised I hadn't seen it flower and didn't know if it would produce pink or yellow flowers so I rooted around in the compost pile and found it (the bulb was slug-eaten) and planted it again in a pot to see what it would do and help me make a definitive ID - next year now I guess.

Oxalis tetraphylla

Also called Iron Cross. We all have personal preferences on weeds, wildflowers and garden plants, this may be considered a garden plant but I would pull it up as a weed if I had it in my garden. I saw this round the corner in someone else's. (tiny herb robert seedling at the top and small rosette of (wild?) rocket at the bottom)

Ox-eye Daisy
another plant I sowed from seed as a wildflower but it can get invasive

This is my first year of these self-seeding. They do look quite prolific.

some smaller seedlings from another year (2017)

quite close to a sea holly seedling (also don't know the seedling top right)

they've appeared in other places, left ox-eye daisy, right anemone? 6-7-2017, see below for a few weeks later

a few weeks later one of the seedlings

that example above with the anemone? 23-8-2017

Oxford Ragwort (Senecio squalidus)

mid-April 2019 in the disused walled east London cemetary I visit occasionally, Oxford ragwort has those distinctive black bits

back in mid-February I saw this local to me, I thought it looked similar to groundsel but a bit different

by mid-April, in bloom and identifiable as Oxford ragwort with those distinctive black bits

Pale Smartweed, Pale Persicaria (Persicaria lapathifolia)

This was growing in a crack on the front path next door. By pulling really hard I managed to get it up and even including the root, as shown below.

I can't remember how easy or difficult this one was to pull up. Much more developed than the one above.

Spotted Persicaria (Persicaria maculosa)

I saw this persicaria down by the canal, July 2017. I think it is different from the ones above but not sure as they are such poor specimens and photos (pic directly above was one of the first weed pics I took and doesn't show the top of the leaves and if they have marks like below. I hope I know better now). I found it in my weed book as Persicaria persicaria but wiki tells me that is not allowed in the latest international agreement on naming plants which I guess the book predates).

Pellitory I've only recently realised there are two, pellitory-of-the-wall which I see quite a lot and upright pellitory which I've only seen from pots I got from freecycle.

Pellitory-of-the Wall (Parietaria judaica)

Large clumps which must be pulled out at ground level. (this is one of the first weed pics I took, must take another esp showing the buds/flowers)

Upright Pellitory (Parietaria officinalis)

This was in a pot I got from freecycle. I did not realize at the time what it was. I knew it was similar to pellitory of the wall (named pic "pellitory-type weed") but only recently came across upright pellitory.

this was a pic of the sprout in the middle (cotoneaster lacteus) but it shows the upright pellitory to the left

it was in another of the freecycle pots

Pendulous Sedge

Small plants, surprisingly easy to pull out - until they turn into larger clumps that must be dug up. Most of the time they are just upright leaves but in the summer (?) they have catkins (not sure what else you call these). NB they look exactly like some of the nutsedge images I've seen. Unless they have the catkins or the flowers I don't know how you tell them apart.

when the sedge is small like the example on the left below it's easy to pull out but when it gets as large as the clump on the right below it needs to be dug out which I did on this clump

Petty Spurge

Phacelia tanacetifolia

I don't know a common name for this. I bought it as a green manure some years ago but this one I saw in a park nearby (May 2019). I don't know if they planted it or it self-seeded. I love the flowers.

Pheasant Berry / Himalayan Honeysuckle (Leycesteria formosa)

August 2018 I saw this on Camden St, London NW1 fully developed and in bloom. I don't know how long it was there but I presume not very long in that position so guess it grew and flowered quickly, unlike the one that self-seeded in my garden (see below) which never bloomed in 2 years.

environment where I saw this

January 2019 there were berries

I had this appear in my garden (July 2014) but wasn't sure what it was. Someone suggested pheasant berry / himalayan honeysuckle so I kept it for a year to see if it would flower. It never did and I got fed up waiting for it and having it take up room on my patio so disposed of it.

March 2017 this has appeared in my wall.

Pigweed (Amaranthus palmeri)

on the pavement near my house I noticed these weeds, at the end of each branch there is a spray of buds, small pellitory of the wall to the right

some smaller plants without the "flower"s on the end of a branch

to the left looks like horseweed, to the right chickweed

an update on the pigweed end of August

a close-up of the "flowers" middle of September

Pineapple Weed (Matricaria discoidea)

I saw this yesterday (16-5-2017) outside Sainsbury's on Camden Rd. Easy to recognise from pics I've seen but I'd never seen it in person before.

Pink-Sorrel (Oxalis articulata)

I saw this in a disused cemetary in east London May 2018. Some of the plants were in the sun as this one in full bloom, some shown below were in the shade so still in bud.

these are some of the flowers in bud, in the shade

close-up of some of the buds

Pink Woodsorrel (Oxalis debilis)

I had this in a pot a few years ago.

Commonly called Plantain but the official name is Plantago, cannot be pulled out, must be dug up

Just saw this specimen today (8-9-2013) which has such well-developed flower spikes, unlike the usual scraggly specimens such as the one above.

Below was one of my unknown weeds/plants but as it's grown I see it's a plantain (Plantago), same as the above.

these are much easier to pull up if identified early, those vertically-veined leaves are distinctive, as are those flowers, shoots just visible on the right of the left plant and on the left of the right plant

different types, apologies as until recently I had field and atlas mixed up

field poppy (Papaver rhoeas)

known as corn or field or red poppy, in bloom May 2018

Month before in April. I had to buy these from the garden centre as attempts from seeds were not very successful.

Atlas Poppy (Papaver atlanticum)

this is the most common one I have self-seeding in my garden

opium poppy (Papaver somniferum)

I don't see these that often

and here is a poppy in flower

there is also the oriental poppy (papaver orientale) but I have not seen that self-seeding

Prickly Lettuce (Lactuca serriola)

I suddenly starting seeing these end of April / beginning of May 2019 locally.

the prickles along the leaf spine underneath are very pronounced

unlike the other examples, this one does not have lobed leaves but it appears to the the same prickles on the stem and under the leaves (also wall lettuce to the left and horseweed to the right)

Prickly Sow Thistle
not to be confused with smooth sow thistle (see below), the leaves may be the same shape (ie lobed) only prickly or more oval-shaped like this one

In the pic below I wanted to show how the leaves curl around the stem.

this one self-seeded between the cracks

and this prickly sow thistle self-seeded on the left in the pot below right (next to a teasel), also pot on the left has foxglove at the bottom and teasel at the top

and that prickly sow thistle seedling from above, leaf is about 5 cm long

I first noticed this prickly sow thistle in the pot with the hosta Sept 2014.

The following spring (April 2015) it seems to have replaced the old leaves with this beautiful rosette of leaves. I still wanted to see it develop and bloom but also wanted the hosta so I pulled up and prickly sow thistle and put it in its own pot. It had a very large taproot, visible below.

Beginning of June 2015 and one of the flowers has developed into a seedhead, like a dandelion, time to dispose of this before any of those seeds with "fluffy bits" (pappus) float away!

a tiny tiny prickly sow thistle, to the right, below, with the yellow flower, mid-July

only about 10 cm tall, after I pulled it out

this fresh green shoot is not the usual prickly sow thistle - although distinctive (prickly along the leaves) and identifiable if you examine it

a prickly sow thistle I noticed around the corner April 2017

Purple Loosestrife (Lythrum salicaria)

I saw this along Regent's Canal today (10-7-2018).

Ragwort/Tansy Ragwort (Senecio Jacobaea)

initial rosette, this is on the patio of the garden next door at the back, the one I help look after

this example I saw in my sister-in-law's garden in northwest London shows the basal rosette similar to the one above

this is in the front garden next door (on the other side, ie not the one I look after) and I'm thinking it's Oxford ragwort as it's more sprawling and less upright than above and the examples on the bee page and South Coast page

Red Campion (Silene dioica)

another plant late summer

Red Clover (Trifolium pratense)

even though these flowers are pink, I think this is "red clover"

Red Valerian see the Identification - South Coast page

Ribwort Plantain

(there's another weed there growing under it towards the bottom, slightly to the right, think it's a horseweed)

Rush, Soft Rush (Juncus Effusus)

small soft rush plant (November), oenothera on the left

same plant following March

I noticed a restaurant on the High St has a couple of rush plants outside it. Sadly, plants like this attract rubbish and cigarette butts but there is something that makes a business owner want to add some greenery to its frontage.

The one above did flower (will find a pic). I continue to have rush seedlings appearing but now I know what they are. At first glance it looks like grass but is thicker than grass. About 2 cm tall at this point.

that seedling above is tiny, below it's in situ in the pot on the left, to the right of the lupin seedling

Salad Burnet (Sanguisorba minor)

thanks for Francine (on FB) for ID'ing this I hope to see it in bloom next Spring/Summer

Salsify ( Tragopogon porrifolius)

I saw this garden escapee on Hampstead Rd, northwest London, end of April 2019.

I first saw this in March and thought it was a goat's-beard. Until it flowers, impossible (for me anyway) to tell the difference between salsify and goat's-beard, both tragopogons.

end of April, very developed bud

scrophularia grandiflora

(with thanks to the RHS forum for ID help), I don't know if this is considered a weed, think I saw it described as a such on a web site but can't find that now, I don't like it and it self-seeded so to me it's a weed!

a few weeks later, yellow flowers on the verge of opening up

Sedum Kamtschaticum

I don't know if this is ever considered a weed but in that location? it sure looks like one. Seen 14-9-2017, Spitalfields, East London

Sheep's Sorrel

I think I've finally found a match for this. It's difficult to say for sure as it's hard to find a really clear pic but this is a very close match from what I can see.

Shepherd's Purse (Capsella bursa-pastoris)

I've seen this in a nearby park and yesterday (21-4-2017) off Hampstead Rd (major road from Camden Town down to the Euston Rd at Warren St). I haven't seen it in my garden but suddenly I seem to be seeing a lot of it in the local area (and Seoul).

close-up of those distinctive seed pods

close-up of the 4-petalled flower in the centre, above it towards the right is a chickweed flower (more petals)

the seed pods developing within the flowers

this is the initial rosette of a shepherd's purse plant

this plant (or plants) shows both the mature plant and that initial rosette

Silver Birch

this is a tree seedling but in this location in a crack in the pavement round the corner from me, it's a weed (thanks to Mike (on FB) who helped with ID'ing this)

coincidentally I also had this appear in a pot which I think is also silver birch

I'm sure this is a rocket (Eastern / London / tall ?) but not sure which specifically. I saw this in St Pancras Old Church churchyard August 2018. Will research further.

another sprig showing flowers and seed pods

Small-flowered Mallow ( Malva parviflora)

I saw this along the Regents Canal near King's Cross (northwest London) in June 2018.

close-up of the small mallow flower

I also saw it locally in a park (June 2019). This view of it growing over the pavement gives some idea of scale.

Small Nettle (Urtica arens)

see also Stinging Nettles

the buds are on small horizontal stems, these 2 pics are not great, I'm going to try to take another (in focus this time!)

Smooth sow thistle (Sonchus oleraceus)

Annual, easy to pull out - roots much smaller than, for example, a dandelion which has thick and deep roots. I'm afraid there are loads of pics of this but it is such a widespread weed and so common, it's worth looking at variations. As other weeds, such as prickly sow thistle and horseweed, may or may not have a well-developed rosette before the main stem shoots up, depending on when they start growing. Smooth sow thistle can have varying amounts of red from none at all to completely red.

1. starting with seedlings

the larger plant on the left has 4 leaves, the smaller plant on the right has 3 leaves and is the youngest sow thistle seedling I have

a bit larger, same 4 basic leaves so far

2. some plants have a more well developed rosette than others

3. full-size flowering plants have extremely variable heights, adapting to their conditions

as a very successful weed smooth sow thistle copes (and flowers) in whatever environment it finds (on a wall next door)

an enormous smooth sow thistle with smooth shiny bright green leaves, March 2017, just down the road in Camden Gardens

Soapwort (Saponaria officinalis)

this is in the garden nextdoor which now is only maintained by me and I like the pink flowers appearing in July so I've left it but it does spread a lot (by underground tubers I think my wildflower book said)

close-up of the soapwort flowers

Spiderwort (tradescantia)

the purple flowers look nice but it can be incredibly invasive

Spotted Medick ( Medicago arabica)

I haven't seen the flowers of spotted medick yet, only the initial rosette and some development of that.

Spotted Spurge (Euphorbia maculata)

seen locally (London NW5) October 2019

close-ups of the leaves reveal the "spots"

common St John's Wort (Hypericum perforatum)

Stinging Nettles

Do beware of these. I have a very painful reaction to this which lasts 12 hours. I don't recall reacting so badly in the past but I've become more sensitive to it so now I wear gloves to weed it and am more careful to avoid touching it. Perennial with tough roots which must be dug out. see also Small Nettle

stinging nettle with flowers

Storks-bill (Erodium cicutarium)

I saw this yesterday (21-4-2017) for the first time off Hampstead Rd (major road from Camden Town down to the Euston Rd at Warren St) so not sure how common a garden weed it is. I haven't seen it in my garden.

those long seed pods look like a stork's bill

I saw this local to me at a park, its rosette of leaves is at the Rosettes page

Wild/Alpine/Woodland Strawberry
this spreads like mad, I find the fruits small and often not that nice

I think this strawberry is the usual garden strawberry, different from those small strawberries above, this self-seeded in the wall. First noticed Sept 2017, although I wasn't sure what it was.

June 2018, some months later and identifiable as a strawberry.

Sweet Rocket (Hesperis matronalis)

a wild flower or a "weed", this one has self-seeded on my brick wall, I like this flower but not in this place

another plant a bit closer that might be easier to see

I saw this one in white in a nearby park, in their wildflower area

Swine Cress (Lepidium coronopus)

This is a tentative identification. Until this year I hadn't seen this before. Now I'm seeing a few occurrences. Initially I'd seen flat rosettes like this but today (12-2-2019) I saw some with shoots similar to hairy bittercress. Will add more photos. Note tiny flower buds in the centre.

Tall Flatsedge (Cyperus eragrostis)

I saw this along Regent's Canal (Camden Town) July 2018

and then end of August 2018

Tansy ( Tanacetum vulgare)

19-7-2019 I saw this tansy on the edge of Epping Forest. The hoverflies were loving it.

I saw this in Spitalfields, east London yesterday (23-6-2018). This somewhat close-up of the flowerhead shows some insects, maybe bees? feeding on it.

This is a Teasel which can be a weed but I grew these as wildflowers for bees and birds. It's a biennial so I planted these last summer. First pic is flowers in bloom, next is after the seed heads have dried out and the third is a teasel plant the first year. Tough plant that must be dug out if not wanted.

as soon as that distinctive texture on the leaves is visible its identifiable as a teasel seedling, below on leaves of 4 and 5 cms, at this point its easy to pull them up if you don't want the teasels in that place, I let a few grow but not to the point where they take over, which they easily do

below the seedling from the bottom of the pic above

on the right when the seedlings have grown and have more leaves, on the left the texture of the leaves is just starting to show

strong and tough and difficult to remove, I like them as a wildflower but worry about them becoming invasive

spear thistle

creeping thistle, in bloom end of June

flowers on a spear thistle in July, I love those flowers but this garden (a neighbour's) is close to being a solid block of thistles, although I do see a huge dock with brownish wilted flowers on the left, it's easy to see how weeds get out of control

close-up of a spear thistle before it blooms (end of June)

thistle seedlings, not sure which variety but if I let some seedlings grow to see variety I need to keep them potted up so they don't get out of control

thistle leaves
a comparison of thistle leaves, on the left creeping thistle, on the right spear thistle

I saw this rosette of a thistle yesterday (10-1-2016), think it's a spear thistle but will go back (it's along the Regents Canal) and see how it develops

Three-Cornered Leek (Allium triquetrum)

This is in bloom in the bitter cold of February (2018).

the flower stems have a trianguluar shape

Tree of Heaven (Ailanthus altissima)

this is the sort of thing you see springing up anywhere and everywhere, like buddleja

I cut off the branch above and it's grown back, surrounded by jasmine (photo taken from my neighbour's garden)

I saw some yesterday that were quite red. I guess their environment affects the colour.

Tutsan (Hypericum androsaemum)

In some places this is considered a weed/invasive plant, not sure about North London (11-9-2017).

Valerian (Centhranthus)

Valerian comes in red, pink and white varieties. I saw this white one recently (June 2016) at a local park in a fenced off wildflower area. I saw red valerian on Hayling Island on the south coast so it's on the Identification - South Coast page and reader Diane recently sent me a pic of her pink valerian so I'm finally pulling all this info together.

close-up of one of the flowers

Great Mullein (Verbascum thapsus)

this is a biennial, here is the young plant, year one

Verbascum flower, year two

This is one of those "weeds" that has self-seeded in the garden.

at first these look similar to foxglove but then their furriness and those distinctive leaves in the center make it clear these are verbascum thapsus

I'm a big advocate of identifying seedlings as early as possible. These are a good example. At first they could be foxgloves or hollyhocks or something else but as soon as those furry inner leaves come out (bottom right, far left), then it's definitely verbascum thapsis and if you have enough of those (or in my case too many!), you can thin them out.

It's been a couple years since I've seen any verbascum thapsis seedlings but this week I noticed this one growing out of a wall by the pavement nearby.

Vetch (Vicia)

I love these purple flowers. I grew it as a green manure next door although I don't know which specific variety. I saw this one at Spitalfields Farm (East London) the other day. Two brown teasel heads at the bottom.

I first planted this as a green manure, after one of the times the garden next door was destroyed with building work. I love those purple flowers but it's quite small. I pulled this up by accident when I was attempting to make room to plant the small hollyhocks (see Seeds).

Violet (Viola odorata)

These spring up lots of places, usually without the flowers which at least provide some interest. I'll try to note how long they last. April 2014 front garden. Most of the year this looks like a weed but it does flower with "violet" flowers. The thing these self-seeders that turn into weeds seem to have in common is their ability to root anywhere.

Another plant after the flowers have finished, May 2013 back garden.

Viper's Bugloss (Echium vulgare)

I guess this is considered a weed in some circles, personally I love it and planted seeds a few years ago. I don't know if this self-seeded from a seed blowing in or grew from a dormant seed in the soil. (plaintain to the right in the pic below, the soil is rock-hard so that will be difficult to dig up)

When I first grew viper's bugloss from seed I did not have much success - think I got 1 plant - and did not take photos of the seedlings/small plants so when these seedlings appeared - or at least when I noticed them enough to take a pic (Oct 2016) I didn't recognise them but now, being impatient to find out what they are, looking around the web I think they are viper's bugloss (also foxglove, viola, snapdragon in that small pot) which I did sow seed for the previous few years but never seemed to get any germination.

a reader suggested fox and cubs so I compared the two, fox and cubs to the left and above of the pot, similar in having rosette of hairy leaves

those all turned out to be viper's bugloss

Wall Germander (Teucrium chamaedrys)

Wall Speedwell (Veronica arvensis)

I saw this local to me April 2019.

I also saw this in the closed east London cemetary.

Wall Lettuce

This is so much like smooth sow thistle but the flower is definitely different although the lower leaves are quite similar. It's quite tall. This one was 85 cm tall - thus the difficutly of taking and posting the photo.

This photo below was taken when the wall lettuce was in situ in the flower bed. I had to pull it out to show the entire plant.

I had previously taken this photo of the small plant in this spot. I thought it might have been nightshde but know I can see it was wall lettuce.

I previously had this as a smooth sow thistle but I'm now thinking it's wall lettuce, although as I didn't let it develop any further I can't say for sure.

Here's another plant I initially thought was smooth sow thistle round the corner (pellitory of the wall to the left) but I now think is wall lettuce, see close-up of the buds next pic.

the buds are looking more wall lettuce, I will see how they develop

the stems with the buds have grown, 10 days later

2 weeks later those buds have opened

I've noticed recently how some weeds are so adept at seeding in a wall, which helps them be so annoying. Below are pellitory-of-the wall (back) and corydalis lutea (front), both of which I picture elsewhere. Also sprouting in walls recently are buddleja, foxglove, verbascum thapsis and sweet rocket, also pictured elsewhere.

Water Figwort (Scrophularia umbrosa)

It says (on wiki) the environment for water figwort must be wet or moist but this environment is definitely dry, a north London front garden. June 2018 fully grown and starting to flower.

beginning of June buds are opening

end of May, buds have appeared

I first noticed this back in November 2017. I could see the leaves were not something I recognised and distinctive with the small leaves below the large leaves on the stem. (strawberries in the background)

Water Mint (Mentha aquatica)

I saw this at RSPB Fowlmere in one of its marshy areas, end of September 2018.

White Campion (Silene latifolia)

I saw this along Regents Canal yesterday (16-5-2017). I guess other times I've walked there it wasn't in bloom.

white campion before it blooms, the flowers make it identifiable, without them nearby I'd never know what this was

White Clover (Trifolium repens)

I saw this along the Regent's Canal near me. It's such a common plant I never really thought about it before but it was so extensive and exuberant I thought I should take a photo and realized I didn't have it in on weed page so here it is finally, June 2018. Also red clover and yellow Yellow Suckling Clover/Lesser Trefoil/Lesser Hop Trefoil

White Deadnettle

I saw this in the park across the road (Camden Gardens)

a close-up of some of the unopened buds

White Stonecrop ( Sedum album)

I first noticed this very small plant in March and this is how it is most of the year.

In July I see it has flowers. (I had been checking it regularly but the previous time was in May and nothing so sometime in June it developed the buds then flowers)

Wild Angelica (Angelica sylvestris)

I saw this at RSPB Fowlmere September 2018.

wild angelica flowers close-up

wild angelica seedheads close-up

Wild Cabbage (Brassica oleracea)

Thanks to Caroline who helped me identify this as Wild Cabbage. This was seen along Regents Canal.

Wild Garlic / Ramsoms (Allium ursinum)

end of March 2019, when it first started blooming

fat buds on the plant below, above it some of those round-leaved new shoots

in addition to the full-size plants, I noticed some first year shoots, with the completely different round leaves

Wild lettuce (Lactuca virosa) see Identification - South Coast

Wild Mignonette (Reseda lutea)

I saw this in east London on 17-6-2018.

closest view I could get, it's behind railings along the railway lines

most of these seedlings are willows that have self-seeded, they have a distinctive red tint (that tall one on the left is snapdragon)

a month later, end of July

The example on the left in the pot below is like the one above but the 2 on the stairs are obviously a different type of willow, if indeed it is a willow, still not sure of either but I decided I wasn't going going to grow on a full-size willow tree so pulled them up. If the one on the left is a goat willow / pussy willow (I have repotted it) I would consider keeping it but not sure how large it has to be before the catkins. I did have a pussy willow before but it got out of control so cut it down. In a pot it may be easier to control.

Willowherb generally 2 types in our gardens:

broad-leaved willowherb shiny bright-green leaves of classic shape, spreads via roots which emerge as rosettes on the surface of the soil, difficult to pull up if part of a spreading root system

short-fruited willowherb thinner leaves, easy to pull up

In the countryside, there is also Rosebay Willowherb. I've never knowingly seen it flowering in a London garden but I have seen them in flower outside urban areas. Having said that, I think it's growing next door but so far not large enough to flower. - update - pretty sure I've seen it flowering nearby last year (2016) but will check and take a pic this year (2017)

Short-fruited willowherb, the fluffy bits at the top, just starting to show below, contain the seeds.

although the willowherb flowers are usually pink, I found this one that's purple the other day

short-fruited willowherb seedlings

tiny early short-fruited willow herb seedling which appeared end of Feb/ beginning of March

Broad-leaved willowherb, by the time I noticed this it's grown multiple stems

rosettes of broad-leaved willowherb growing from the spreading roots

I noticed some broad-leaved willowherb plants in the back garden and when I pulled them up saw two different sprouts on the roots, red leaved (top below) and green (below in the pic below) and then close-ups of each in the following pics.

I think this is broad-leaved but I'm not even sure. At this stage it looks as if it could be either.

Great Hairy Willowherb

great hairy willowherb on the left, horseweed on the right

I saw this today along Regent's Canal (10-7-2018).

I saw this example yesterday.

Rosebay Willowherb

June 2018, this was the first rosebay willowherb I've seen in London, rather than a very tall drift of plants in West Sussex (see below). This was at my local dump.

even smaller than the examples above, I saw this on Camden St, London NW1 today (8-9-2018)

It was only about 30 cm tall. I see berries? (bottom left) I didn't notice them when I took the photo. They were from previous flowers? I certainly haven't noticed this plant before. So it had time to grow, flower and produce berries in a short space of time?

a few years ago I had these seedlings but sadly never saw them reach flowering so I guess I cannot confirm they are rosebay willowherb

That (on the left above, taken beginning of March) has turned into this, middle of June.

3 months later the above has grown a little taller but otherwise little change.

following year, to the right, other plants are nigella

and here's another pic, I wanted to make sure that red stem showed up clearly (the nigella has a red stem as well)

Rosebay Willowherb has a very distinctive veining on the leaves, they don't extend to the edge of the leaf:

compare with a short-fruited or broadleaved willowherb leaf:

medium-sized plant, second year, discarded after I established what it was

I saw these, full-sized rosebay willowherb plants at the side of the road in West Sussex

This is Wood Avens also called Herb Bennett (Geum Urbanum). I'm sure this was "recommended" by the RHS but they are now calling it a weed. This was one of the first weeds I noticed and took photos of - and I still don't like!

I noticed today (mid-June) that the wood avens were in bloom The following 3 photos show the wood avens flowers.

One thing I've recently realised about wood avens is that the young, first leaves at the bottom of the plant are differently shaped from the older leaves at the top. I guess I thought all the leaves on a plant were one shape. Realising this helps in identifying weeds. I didn't realise that the plant below and the plant above are both wood avens but obviously the leaves are completely different.

A young wood avens some weeks later.

Some weeks later, differently shaped leaves at the top of the plant.

After the Wood Avens have flowered there are prickly burrs with the seeds.

Yarrow (Achillea millefolium)

I don't know why I hadn't seen this before in London until this week. I did see it on Hayling Island (see Identification - South Coast). This was in Allen Gardens, Spitalfields (East London).

Unknown Weeds

Also see the end of the Plant Identification page for my unknown plants. Hard to tell sometimes if something is a "plant" or "weed" but here I guess I can decide.

This is also at the Weed Rosettes page. I first saw this in January. Six weeks later and no change.

the plant above is shown below, towards the edge in the middle

in this same area is the seedling below

these are along the Regent's Canal (acanthus on the right, pellitory-of-the-wall behind), as they develop more they should become identifiable

and another umbellifer along the canal

mayweed? scented or scentless?

this looks like bristly ox-tongue but I have never seen small rosettes growing up a main stem like this, seen January 2019 at Rainham Marshes

wild lettuce (Lactuca virosa) first year.

I saw this on Hampstead Rd near Euston Rd in London. I see photos similar to this that are being called "wild lettuce" but also a taller plant with quite different leaves (see South Coast page), is that the second year plant? or are two different plants being called wild lettuce and what exactly are they?

January 2019, Rainham Marshes, I know this is the most difficult kind of identification - in the winter, no flowers and I've only seen it once and probably not again, but the leaves are quite distinctive. Think this is goat's-beard

This is very knapweed-looking but it's not quite like the lesser and greater knapweeds I have in my garden. And it's also very early to have such developed buds (4-3-2019).

a couple more smaller examples

a little bit like hedge mustard, but fuzzier, two examples close to each other


American history

The Cannabis plant can grow up to 18 feet tall. In the Americas, Cannabis extract was a popular medicinal drug in the 1800s. But in the 1900s, the tide began to turn against the drug. In the 1920s, Mexican immigrants became associated with the smoked, recreational version of the drug, and anti-immigrant sentiments fueled marijuana prohibition.

By the 1930s, marijuana was banned in 24 states. The newly minted Federal Bureau of Narcotics launched a campaign against the drug, and newspapers fueled hysteria with headlines like the 1933 Los Angeles Examiner's "Murder Weed Found Up and Down the Coast &mdash Deadly Marihuana Dope Plant Ready for Harvest That Means Enslavement of California Children." By 1937, Congress passed the Marihuana Tax Act, which effectively banned marijuana except for a few medicinal purposes, according to "Smoke Signals: A Social History of Marijuana &ndash Medical, Recreational and Legal" (Scribner, 2012).

In the 1950s, the Narcotics Control Act and the Boggs Act stiffened penalties for marijuana possession, with first-time offenses requiring two to 10 year sentences and a minimum $20,000 fine, according to PBS.org. Penalties were relaxed in the 1970s, but President Ronald Reagan increased federal penalties for marijuana possession in the 1980s. On the federal level, marijuana is now regulated under the Controlled Substances Act as a schedule 1 drug, meaning the government considers it to have a high potential for abuse with no legitimate medical or therapeutic uses.

However, numerous states have decriminalized or legalized marijuana. As of early 2017, 26 states and the District of Columbia have legalized pot in some form of medical and/or recreational use, with other states soon to follow.


Jimsonweed

Our editors will review what you’ve submitted and determine whether to revise the article.

Jimsonweed, (Datura stramonium), also called thorn apple or devil’s snare, annual herbaceous plant of the nightshade family (Solanaceae). Possibly native to Central America, the plant is considered an invasive species throughout much of the Northern Hemisphere. It was used by Algonquin Indians in eastern North America, among other indigenous peoples of the Americas, as a hallucinogen and intoxicant. The leaves contain potent alkaloids (notably hyoscyamine and hyoscine), and all parts of the plant are poisonous if ingested.

Jimsonweed grows to a height of 1 to almost 2 metres (up to 6.5 feet) and is commonly found along roadsides or other disturbed habitats. The plant has large white or violet trumpet-shaped flowers and produces a large spiny capsule fruit to which the common name thorn apple is sometimes applied. The stems are green, sometimes tinged with purple, and bear simple alternate leaves with toothed to lobed margins.

This article was most recently revised and updated by Melissa Petruzzello, Assistant Editor.


Preventing Palmer amaranth in Minnesota

In September 2016, Palmer amaranth (Amaranthus palmeri) was initially discovered and confirmed in Minnesota. Efforts to eradicate this weed are critical to Minnesota’s commodity crop producers.

Palmer amaranth is on the Minnesota Noxious Weed List as an “Eradicate” weed. This legal status means the plant must be destroyed and that no transportation, propagation or sale of this plant species is allowed.

Report possible infestations to the Minnesota Department of Agriculture (MDA) at 1-888-545-6684 or [email protected]

Handling Palmer amaranth

Palmer amaranth isn’t native to the northern United States, but has spread northward from southern states. It’s been confirmed in Wisconsin, Iowa, Illinois and Nebraska from 2011 to 2013, South Dakota in 2014 and other northern states.

In August 2016, it was discovered in newly seeded Conservation Reserve Program (CRP) land in Iowa, and that September, it was confirmed in Yellow Medicine County in Minnesota.

Palmer amaranth is the most competitive and aggressive pigweed species. It’s related to waterhemp and, like waterhemp, it emerges throughout the growing season, from May to August. However, Palmer amaranth is much more aggressive than waterhemp, growing 2 to 3 inches a day.

Herbicide resistance

Palmer amaranth can quickly adapt to herbicide management tactics that don’t include diverse effective sites of action (SOAs), ultimately limiting control options. In the northern states, Palmer amaranth is expected to be resistant to multiple herbicides, including glyphosate (SOA group 9) and acetolactate synthase (ALS) inhibitors (SOA group 2).

Palmer is dioecious, with male and female plants. Outcrossing results in rapid spread of herbicide resistance.

It’s a prolific seed producer, with a single female plant typically producing 100,000 to 500,000 seeds.

Timing of herbicide application is critical. Effective preemergence herbicides need to be followed by timely (plants less than 3 inches tall) and effective postemergence herbicides.

Threat to crop production

Palmer amaranth infestations have caused substantial yield losses and greatly increased weed management costs in cotton, soybeans and corn in the southern states. Once established in the northern corn and soybean states, it’ll likely do the same and significantly increase costs and decrease yields.

Identifying Palmer amaranth

First, scout your fields with a particular focus on native seed planting areas.

Look for pigweed plants that can reach heights of 6 to 7 feet in unmown areas, as well as the following key characteristics:

Leaves: Ovate- to diamond-shaped leaves, which give it a poinsettia-like appearance (Photo 3). No hairs.

Inflorescences: Prolific seed producer with a long main terminal seed head (inflorescence) that’s up to 3 feet long (Photos 1 and 4). Female inflorescence have sharp, spiny bracts (Photo 5).

Plant characteristics: No hairs on stems and leaves, unlike redroot pigweed. Petiole is as long as or longer than the leaf (Photo 6).

Photo 3: Poinsettia-like appearance of Palmer amaranth. Source: Rebekah D. Wallace, University of Georgia, Bugwood.org.

How to handle infestations

Palmer amaranth’s legal status as a state-prohibited noxious weed on the “Eradicate” list means the plant must be destroyed and that no transportation, propagation or sale of this plant species is allowed.

This law gives MDA, county, city and township officials the right to inspect land areas believed to be affected by this weed and ask owners to destroy the plants. It also allows MDA officials to investigate where potential seed lot contamination sources are occurring.

How to report

If you suspect a weed is a Palmer amaranth, email the following to [email protected]:

The plants’ location. Be as specific as possible.

A description of the area where the plant was found.

Photos (similar to Photos 4 to 6 in the identification section).

Petiole (where the leaf connects to the stem)

Why to report

This information helps the MDA understand the weed’s current distribution and its potential to spread to your fields and adjacent lands. Reporting also allows local officials to help monitor the site in subsequent years to make sure there were no escapes. This is particularly important if land ownership changes in the near future.

Destroying the plants

After photographing and reporting, destroy the plants in question.

Note there’s a very short timeframe to accomplish eradication. However, due to the economic significance of this invasive weed, it’s worth our collective effort to try.

Small populations

If the Palmer amaranth population is small in number:

Place them in a large paper bag.

Remove it from the field to a site suitable for burning the plant.

Again, weed it, bag it, drag it and burn it. Please don’t literally drag it it just makes the process easier to remember.

Larger populations

For a larger population of plants at the mature stage of the weed’s life cycle, particularly when the seed is being set:

Clean off the mower on-site. This prevents the spread of any weed seed shed onto the mower.

Mowing doesn’t kill the entire plant, but it’ll keep the seed on the ground in the affected area where insects and rodents can feed on it. Mowing will reduce movement away from the affected area. Plus, any seed that germinates the following year will have to compete with the more established plants that surround it.

It’s important to closely monitor the affected and surrounding area the following year to make sure there are no weeds that escaped detection or seeds that have moved into adjacent lands. By reporting your affected site to the MDA, they’ll be able to assist you with this monitoring procedure.

Palmer amaranth has spread from the south through:

Contaminated feed, including cottonseed and hay.

Contaminated grain and seed.

Farm equipment and manure.

Palmer amaranth in manure

The Minnesota Department of Agriculture has identified manure as a pathway for Palmer amaranth introduction to the state. Specifically, Palmer amaranth seeds that contaminated sunflower screenings were fed to cattle. Some of those seeds survived digestion, and when that manure was spread onto cropland, those seeds germinated.

There are many factors that affect seed viability in manure. The following sections describe practices that may help reduce Palmer seed viability in feed and manure and thus, reduce the risk of applying contaminated manure to the field.

Reducing Palmer amaranth seed in feed

Don't assume animal digestion will kill all of the seeds

Though it will reduce weed seed viability, simply feeding the contaminated material to livestock will not eliminate all Palmer amaranth seed. Grass and soft-coated broadleaf seeds are more easily destroyed in digestion than hard-coated seeds – such as Palmer amaranth. In rumen animals, such as cattle, 27% of amaranth seed remained viable after digestion. The gizzard digestive system of poultry is highly effective at destroying weed seeds, and only 3.5% of Palmer amaranth seeds fed to ducks were recovered and found viable.

Ensile the feed (if appropriate for feed type)

The fermentation and heat generated during ensiling is quite effective for killing weed seeds. Just one month after contaminated alfalfa haylage was stored, amaranth seed viability dropped by 41% and in corn silage, the drop was even greater at 60%. Logically, seed viability continues to decrease as silage storage time increases. Eight weeks of ensiling killed up to 87% of viable amaranth seed and when feed went through both ensiling and rumen digestion, the seed mortality increased to 89%.

Reducing Palmer amaranth in manure

Compost solid manure

Internal heat generated by properly composting manure will kill most weed seeds – even the hard-seeded Palmer amaranth. The key word here is “properly.” Aged manure is not composted manure. Proper composting requires active management and must be monitored and aerated for correct weed-killing conditions to develop.

Temperature and moisture are the two most crucial elements for seed mortality in compost. For Palmer amaranth, researchers found that sustaining the compost at 140⁰F for three days will virtually eliminate seed viability, so long as a minimum of 35% moisture is maintained. To account for temperature and moisture uniformity issues that are prevalent in composting, exceeding these minimums and composting at 160⁰F for four days with 50% moisture is recommended. Another study found that it took between 21 and 50 days of composting with proper management to eliminate amaranth seed.

However, research trials reached 0% viable weed seeds under the best compost management practices possible in a very controlled environment. In contrast, an actual on-farm survey of composting sites found that while composting did reduce weed seed viability 90-98% over six to eight weeks, there was still potential for seed survival. This seed survival - or mortality escape - varied by operation and weed species. It is theorized that this mortality escape is due to cooler pockets that do not sustain high temperatures for long enough. Therefore, just because manure has been composted does not necessarily mean it is weed seed free.

Liquid options are limited

Obviously, liquid manures cannot be piled for composting, and pit storage – including the anaerobic conditions in deep pits – does not significantly contribute to amaranth seed mortality. Barring expensive heat treatment of the manure, the best option here is application followed by diligent and frequent scouting.

Don't rely on anaerobic digestion

Though anaerobic digestion of manure may reduce seed viability of some weeds, it has not been found to affect amaranth germination beyond the benefits of animal digestion alone.

Field application of contaminated manure

Transport it to nearby fields that can be easily and frequently scouted. Even if the feed was ensiled and the manure was composted before spreading, it’s still possible for weed seeds to remain viable. A 98% reduction in viability seems sufficient, but even low seed survival rates can be problematic. A survey of fresh dairy manure in New York found an average of 75,000 viable seeds per ton and a range of 0 to 400,000 seeds. Two percent survival of 75,000 would leave 1,500 viable seeds remaining per ton. Applied at 8 tons per acre, that would increase the weed seedbank by 12,000 seeds per acre. This “numbers game” is especially precarious in the case of Palmer amaranth since Minnesota hopes to entirely eradicate it, as it would be fairly easy for just one or two seeds to slip through to the field.

Apply the highest rates of manure (according to MN Pollution Control Agency guidelines) to the fewest number of fields as possible to minimize the spread of the seed. If these fields can be planted to more competitive crops such as alfalfa, grass pasture, or small grains that could also help by smothering the weed.

Scout fields after application

It is crucial to scout early and often for Palmer amaranth in fields that have received possibly-contaminated manure. Since this weed has an extended emergence period ranging from May through July, it is important to continually monitor fields.

If you find a plant that you suspect is Palmer amaranth, be sure to follow the directions in the "How to handle infestations" section above.

Conservation plantings

In Iowa and Indiana, the most recent infestations were in newly seeded conservation plantings (i.e., Conservation Reserve Program (CRP), wildlife, pollinator and cover crop plantings) where the seed mix was contaminated. Ohio and Illinois also reported contaminated conservation seed mixes as a source of Palmer amaranth introduction.

Palmer amaranth may not persist in areas being established for conservation habitat. This is because Palmer amaranth should be crowded out once native, perennial vegetation establishes. However, until perennial plants become established, Palmer amaranth may produce enough seed to establish a seed bank and move into neighboring corn and soybean fields.


Life-changing impact

Explore some of our current research in the plant and soil sciences and see how New York's Land-Grant university is making an impact both in our home state and around the world.

Africa South America Asia North America

Plant Leaf Identification: How To Tell Plant Leaves Apart

In order to identify a plant, you need to recognize characteristics like size, form, leaf shape, flower color, or fragrance. Then, you may link those characteristics to a name. Accurate identification means you can figure out how the plant grows and the care it needs.

Since plants only carry flowers for part of the year, leaf identification is often more useful. Read on for information on how to tell plant leaves apart, including tips on identifying flowers by their leaves.