Welcome to the weed atlas!
The Weed Atlas compiled here is hardly complete and subject to review and update. I'm including those weeds that I find here in New York City -in yards, in the cracks of sidewalks, in parks, on piers. NYC enjoys most of the weeds common to eastern North America, so that if you find yourself here and the weed you are trying to identify is in, say Clearfield, PA or Springfield, MA, the atlas may still be of use to you.
Many of us get online now when we want to identify something, and that is no less true for the weeds in our yards. For years I depended on the book Northwest Weeds as my weed ID source because no proper book had been published for the Northeast. Today, that is no longer the case, so that some of what I publish here has been cross-referenced with the excellent Weeds of the Northeast by Uva, Neal, and DiTomaso.
Deciding what is a weed and what is not is a fool's errand. But for the sake of limits, I define weeds to be those plants that grow of their own accord in areas disturbed by the activities of humankind, and are, by my definition, regionally and often globally, ubiquitous. Some weeds can also be distinguished as invasive, although not always alien, to a region. Weeds go wherever we do.
The atlas follows in alphabetical order, with the botanical name first when I can accurately state it. All listings have at least one photo, which can often be clicked on for a larger image to help in identification. Each listing will also provide a link to another site with broader description and more photos to further your research. Some of the plants listed are noted as edible, but please don't eat anything unless you have positively identified and properly prepared it.
WEEDS OF NYC
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Achillea millefolium, Common Yarrow, Milfoil, or Field Yarrow
Common Yarrow is a perennial plant often associated with old cultivated fields and sometimes lawns. If it is mowed, it can form mats of fine foliage close to the ground. Of course, field yarrow is related to the garden Yarrow, bu its flowers are generally white, sometimes with a pinkish tinge, and its foliage is very finely cut. Garden Yarrow has been bred to have many colors and in some varieties, soft gray foliage. I grow both kinds in my garden, but beware, the field Yarrow spreads rampantly.
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Ailanthus altissima, Tree of Heaven
Young tree, often found growing on fencelines and in pavement cracks.
Ailanthus will grow almost anywhere, roofs, windowsills, cracks in pavement. It has an extremely aggressive nature and is incredibly resistant to permanent removal. I once removed a concrete pad from a backyard in Brooklyn. Underneath this old concrete, hundreds of little ailanthus roots just waiting for the right opportunity. Can be taken out, but requires perseverance. Often confused with Sumac. Below are two photos, ailanthus on the right, sumac on the left. The ailanthus will get much taller than the sumac. The sumac has deep red, upright seed heads, the ailanthus drooping pale yellow seed clusters.
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Alliaria petiolata, Garlic Mustard
Garlic mustard.
I spied thousands of Alliaria petiolata or 'Garlic Mustard' plants and hundreds of Hesperis matronalis or 'Dame's Rocket' from a Metro North train window. I saw several good looking clumps of Garlic Mustard in Cadman Plaza Park this spring, where I pulled some leaves and crumpled them in my hands to catch the faint, slow release of garlic scent they're named for.
Dame's rocket -also a mustard.
A relative of these is a cottage garden favorite, the cultivated Dame's Rocket, as seen here in a garden I know. I first became aware of the mustards when I lived in southern New Mexico -it was the plant growing along all the ditches in winter. Mustards tend to be cool weather biennials, and in our region that means you'll see then green up and flower in spring.
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Amaranthus spp., Pigweed
Amaranth comes in many forms, some weeds, some culitvated for their leaves, roots, seeds or for ornamental uses. There is a woman who comes by late spring into summer pulling the amaranth from the fence line along the sidewalk to eat, I presume. I assume she understands that local dogs pee on local fences. There are several varieties of this plant and easy to misidentify within the species (see all these forms of A. retroflexus). All have the telltale inflorescence, although with variations in length, bushiness and color. It is an annual plant that tolerates dry conditions. Pull it up early and don't let it go to seed as the thousands of seeds per plant can last up to thirty years in the soil.
Amaranth gone to seed.
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Ambrosia artemisiifolia, Common Ragweed
Common Ragweed. Too many people think that this is not the culprit for their allergies, yet it is. Flowering at the same time as Goldenrod, showy Goldenrod often gets the blame. Even allergy pill commercials seem to show yellow flowering plants in their scenes.
Ambrosia is a mystery to me, but
artemisiifolia refers to the leaf structure which is similar to many
Artemesia plants like the mugwort found one entry below this one. To some the foliage looks like that of French marigold.
The stems of Ragweed are reddish and highly pubescent -meaning there is hair.
Ragweed flowering stems shoot straight up, sometimes leaning over. From above they look mostly green with hard to see flowers.
How do you know that Ragweed is responsible for your allergies? The flowers all face the ground. Flowers that face the ground are less likely to attract pollen-spreading insects like bees and flies. Flowers that are bright and yellow, facing outward like Goldenrod are insect pollinated. Ground-facing flowers depend on the swaying and shaking caused by the wind. This same wind picks up the pollen as it drops out of the flower, spreading it several feet or yards or miles. Ragweed is wind pollinated, and that, my friends, is something to sneeze at.
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Artemisia vulgaris, Mugwort
Artemisia vulgaris is the weed of our metropolitan life. This is the plant that greens brownfields, empty lots, roadsides, and overpass embankments. One summer along the waterfront in Williamsburg, I witnessed thousands upon thousands of lady bugs crawling over the practical monoculture of mugwort growing there. All that red and green, quite amazing.
Some people confuse this plant's young growth with Chrysanthemum. Please don't. The underside of the Mugwort's leaves are fuzzy and light gray, and its foliage aromatic. The leaves become thinner and elongated as the plant matures and its flowers are inconspicuous. Mugwort is perennial and spreads via vigorous rhizomes -so pull, pull, pull or enjoy the greenery. I have noticed one sidewalk garden in Red Hook that seems to have struck a fine balance between their perennials and the mugwort.
At flowering maturity, mugwort will take on this appearance -rangy with small lanceolate leaves, and flowers.
Mugwort flowers up close.
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Asclepias syriaca, Common Milkweed
Milkweed jumps out thanks to its broad, fleshy leaves with pubescent undersides, mass of flowers, and erect habit in fields and meadows. A native to North America east of the Rockies, it is only considered a weed in disturbed areas like old farm fields by crabby old farmers. It likes sandy soil and is common amongst the community garden plots in Ft. Tilden.
The leaves have a light gray pubescence on the underside.
Asclepias syriaca exudes a milky sap when any part is torn and is a favorite of the Monarch Butterfly in its larval stage. Milkweed is known to produce useful fibers, and its young shoots, buds, and flowers are edible when cooked. But do not confuse it with the Dogbanes, which look very similar if you are not looking closely.
Apocynum cannabinum, Indian Hemp or Hemp Dogbane. Notice its reddish stems and different flowering character. Indian Hemp will produce a milky sap just like Milkweed.
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Celastrus orbiculatus, Oriental Bittersweet
In summer the vine is green with small cream-colored spots. In autumn, the vine hardens and darkens.
Late autumn berries, commonly used for wreaths.
Oriental Bittersweet, native to eastern Asia, loves fence rows. I first came across this vine on the stockade type fence around our backyard and you'll probably find it on chain links just like the one above. The berries hang on long and are a favorite of birds, so despite their good looks, if you want it gone, get it before it sets fruit. Just make sure it's not the native variety, American Bittersweet, Celastrus scandens, by checking out this great ID document. The decorative possibilities of the vine in late autumn are well known, but selling it live or cut is illegal in some states. No wonder it's 'bittersweet.'
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Chenopodium album, Lamb's Quarters, also Pigweed
Mature plant, streetside.
The 'goosefoot' name refers to its leaf shape.
Chenopodium (the name: cheno-goose, podium-foot describes the leaf shape) is commonly known as Lamb's Quarters. Some call it Pigweed, confusing it with the Amaranthus species. The common name may hold water however, it seems taxonomists may be changing the Chenopodiaceae classification to Amaranthaceae. This weed grows everywhere in the city and is a common weed from my childhood yard. Drought, sandy soil, and compacted earth are favorite locations for this plant. It can stay compact and bushy, yet sometimes is open and willowy . Young leaves are eaten in salads or cooked and some make a meal out of the seeds -in this way it is similar to amaranth. I like it for its intense magenta leaves often found half way up the plant.
Mature lamb's quarters with magenta leaves at its base.
Fruit in later summer.
Magenta fruit in autumn.
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Cynanchum nigrum, Swallowwort
This one's called Swallowwort, cause it'll swallow anything in its path.
The fascinating flower, not quite black, more dark plum colored.
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Commelina communis, Asiatic Dayflower
The Commelina species here is the non-native, asiatic variety. There are a few tell-tale traits to divine the two, which you can see here. Here in NYC, you probably have Commelina Communis. Its called Dayflower because the flowers are with us only for a day. Its quite a beauty and I let it be in corners of the garden. It spreads, like other plants in the Spiderwort family, but this Dayflower is easy to pull once it sprouts up.
Dayflower with a common growing companion, Smartweed.
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Draba verna, Whitlow Grass
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Erigeron philadelphicus, Common Fleabane
This specimen sprouted in early spring in my Brooklyn garden. It began blooming in mid-May. Fleabane is native to these parts, and belongs to the great family of Asteraceae.
It has a pleasing form until flowering, at which time the leaves begin to yellow and the stems get wily.
Pretty, pinkish-white daisy-type flowers. Is it the bane of fleas? I hope I'll never know.
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Fallopia japonica, Japanese Knotweed
Attractive plants make successful weeds.
The heart shaped leaves on young red stems give it away.
Don't let those quaint and attractive leaves of the young Japanese Knotweed fool you -the bottom photo shows how large these can get when not attended to. An attractive herbaceous perennial, it escaped garden cultivation years ago to become a major weed of wetlands, roadsides and yards. The specimen above grows in a fence row in my Brooklyn neighborhood, and has sent its rhizomes to the sidewalk strip adjacent to it where it grows a similar height each year. Persistent, one must continually remove rhizomes, roots and stems. The young shoots are edible, making spring pulling more tolerable.
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Hedera helix, English Ivy
English ivy scrambling up trees and across the ground in Prospect Park.
Hedera helix may not be a weed to many, and I don't always consider it a weed myself. But this plant does escape and does get out of control. I think we may have all seen at least one tree with this plant growing all over it. For the many who have shady spots in front of or behind their homes, this has been the answer to concrete. However, there are many different varieties - so choose one that is attractive and less invasive. To remove, simply pull it up. It roots from cuttings of the vine, so remember to pick up the pieces.
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Lamium purpureum, Purple Dead Nettle
Purple Dead Nettle is common in fallow fields, disturbed areas, and even lawns. This specimen was found in a community garden plot in late March, having sprouted after the plot laid fallow over winter. It's similar to garden Lamium and a quick spreading ground cover.
Its flowers are attractive to bees because it blooms profusely when little else does. You'll often find Purple Dead Nettle blooming near a common look-alike, Henbit.
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Lamium amplexicaule, Henbit
Henbit will bloom during cool weather, just like its cousin, Dead Nettle, and you'll often find them side by side, possibly confusing them because of their purple flowers. Henbit has a tap root, so pull when the soil is wet for greater effectiveness. Apparently the name Henbit reveals how chickens like to snack on some part of the plant, and some say it is an edible spring green for those folks not too chicken to eat it.
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Linaria vulgaris, Butter and Eggs
This nice specimen of Linaria vulgaris was found on a fence line at the sidewalk's edge in Red Hook, Brooklyn. Likes well drained soil, so I suppose a demolished building's old site will do. Butter and eggs refers to the coloring of the flowers, but this lovely weed has dozens of colloquial names.
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Malva neglecta, Common Mallow
Mallow leaf.
Malva neglecta is a common roadside, lawn, and garden plant. It belongs to the large family of Mallows that includes Hollyhocks, Swamp Rose, even cotton. Some call Common Mallow by the name "cheeses" due to its round cheese-wheel like fruit. The flowers range from white to pink to purple and are often quite attractive, no doubt aiding this plant's success in some yards. To pull it, you should soak the ground first as it has a tough taproot. Apparently it has edible leaves and roots and a long association with humans.
Mallow patch.
Mallow flower.
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Oxalis stricta, Yellow Wood Sorrel
Yellow Wood Sorrel is one of those North American natives that is also native to Europe and Asia. It's therefore ubiquitous and most often considered a weed. It's often confused with, or called, clover because of its trifoliate leaves. Apparently edible in limited quantities, with a somewhat lemony flavor.
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Phytolacca americana, Pokeweed, Pokeberry or Poke
Pokeweed bush.
Phytolacca americana is native to the continent. As a kid, I used to let the pokeweed grow real tall in our backyard and then harvest the stalk, drying it in the sun for a week. Afterwards I made spears with the woody and straight stalks. Us kids also made "wine" and dye with the berries. We never drank that wine because I guess we intuited that this was a bad idea. And of course, it is a bad idea because all of this plant is poisonous. However, it was common to boil the young greens in the American South. You may still be able to buy cans of it down there.
Pokeweed in a can.
Poke berries are loved by many birds. While this plant is perennial, it also propagates via seeds dropping from all those birds. Pull to remove from the garden, but leave some in the more wild parts for the birds. I find pokeweed to be attractive, but that may be just nostalgia for my early years showing its influence.
Pokeweed leaves, berries and rose-colored stems.
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Plantago lanceolata, Ribwort Plantain, Narrowleaf Plantain
Basal rosette.
Mature flowering plant.
Flowers.
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Plantago major, Common Plantain, Broadleaf Plantain
Single plantain with seed stalk.
A patch of plantain.
Pantago major is one of the most common weeds of roadsides, lawns, and pathways. This plant will grow in wet or dry compacted soil, areas little else can. There are native species of this plant in the area, but if it's in your garden it is likely to be this one. Best method for eradication is to pull it after a good soaking rain and keep your soil aerated. Or live with it as this plant has a history of herbal usage.
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Polygonum caespitosum, Long-bristled Smartweed, Oriental Lady's Thumb, Smartweed
There are several native and non-native forms of Polygonum and some are very invasive. The one we most commonly find in our gardens is Polygonum caespitosum. As I stated in Our Weeds, part 1, I often leave this weed in the garden for its ability to fill blanks with its attractive foliage and pink flowers. It self-sows abundantly so that there is never a shortage of plants. The young plants are distinctive and easy to pull.
A good sized patch of Smartweed.
It can be a nice garden plant -for a weed.
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Rumex acetosella, Red Sorrel or Sheep Sorrel
I think Red Sorrel is really good-looking in a field of grass, where it is likely you'll find it. It is also found on other disturbed areas like roadsides or brownfields. It tolerates poor drainage and acid soils. If you have it, dealing with those conditions may be part of the mitigation process. Apparently it has a strong sour taste and has been known to be fatal to sheep.
Red Sorrel.
Red Sorrel flowers are sometimes more yellow.
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Rumex crispus, Curly Dock
This stand of Curly Dock has been getting stronger by the year. I think we lose neighbors to it. It may eat people.
Aphids enjoying the succulent stems of Curly Dock.
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Silene latifolia (alba), White Campion
White Campion is an attractive, flowering weed of pastures, meadows, and other weed-filled places. Maybe you don't want to pull it, but if you do, it has a tap root. Wet the soil thoroughly first to make the pulling easier.
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Tragopogon dubius, Western Salsify
You might think
Western Salsify is a giant dandelion. Common throughout the West, it is making inroads into the drier parts of our area.
Dandelion-like seed head can be up to 6 inches across.
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Trifolium repens, White Clover
Trifolium repens is a part of the Pea family of plants, and one of many Trifolium (clover) species including Red Clover and Hop Clover. If you do a web search of the word clover you'll get equal parts how to kill it in your lawn and how to grow it in your lawn. Either way you have it, clover is an introduced species commonly used as forage for livestock and honey production. White Clover is a perennial, spreading over ground and rooting at its stem nodes. Pull it or leave it. It does form patches, though some like it more than grass.
A community of white clover.
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Trifolium pratense, Red Clover
Red Clover is much like the white clover, but more upright and typically larger. It is often found in old farm fields and roadsides.
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Veronica persica, Persian Speedwell, Birdseye Speedwell.
I found this specimen of Persian Veronica in an athletic field in Red Hook, growing at a bland time of the year, maybe late March. I yanked it up and planted it in a barren spot underneath a rose. Now it cannot be stopped, but is easy to pull should it go too far.
Flower.
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