A Celebration of Sidewalk Weeds

This was supposed to be a great weekend for botanical excursions in the Adirondacks: exploring Valcour Island in Lake Champlain for some of New York's rarest lime-loving plants, and then on Saturday, monitoring the rare alpine species at the summit of Whiteface Mountain, with both trips led by some of the leading botanists in the state.  But both trips were canceled because of threatened thunderstorms.  Darn it all!  This is getting to be a pattern.  Two years ago I was all set to join five passionate botanists on Ontario's Bruce Peninsula for a week's adventures during orchid season, when I fell and broke my kneecap a week before we were to meet.  Then just this spring, I had arranged to join a botanical excursion in Georgia's Okefenokee National Wildlife Refuge, but just two days before the trip, the swamp caught fire and all access was closed.  Darn again!

I was feeling pretty bummed, all right, so I went for a walk around town to try to lift my spirits. And of course, wildflower nut that I am, I couldn't help stopping every few feet to examine the plants sprouting up from cracks in the sidewalk or gracing the gravelly edges of city parking lots.  What an amazing bunch of tough little plants!  They bloom beneath the blistering heat of the sun, thrive despite hordes of trampling feet, and endure the occasional urine soak from both dogs and drunks.  And still they put forth some very pretty flowers.  Or at least, some interesting ones.  Here is just a sampling of what was underfoot this Friday.


Asiatic Dayflower (Commelina communis), an introduced species that offers us its shimmering royal-blue beauty for only one morning.  But then another bunch blooms tomorrow.  This tiny hoverfly is loving this flower for other things than its beauty.  We could too, I understand, since I have read that the flower is edible.  You'd have to eat it for lunch, however, since it shrivels by mid-afternoon.

Black Medick (Medicago lupulina), another introduced species, one that spangles the grass along almost every sidewalk.  I am very happy that it has supplanted most of the grass in my lawn extension, since it never grows more than ankle high, doesn't wilt during drought, and battles the crabgrass back. And really, isn't it pretty?

Carpetweed (Mollugo verticillata).  Although this tiny-flowered sprawling plant is said to have originated in the American tropics, it is hard to call it an introduced species up here, since archaeological evidence has demonstrated its presence all over North America for a least 3000 years. Known to be edible and nutritious, it is also said to have several medicinal qualities, including anti-fungal and anti-inflammatory properties.  All these amazing properties in one tiny ubiquitous weed!

Centaury (Centaurium erythraea), a tiny flower that announces its presence by its vivid color.  Although naturalized in parts of North America, where it thrives in thin gravelly soils, it originated in Europe, where it is said to be used medicinally for patients with gastric and liver disease. I use it simply to delight my eyes!

Common Chickweed (Stellaria media) is another European plant now widely naturalized across North America.  Although despised by farmers as a crop-diluting weed, it is said by some to have many medicinal uses, and there's no disputing its nutritious edibility, by either humans or poultry. Chickens certainly love it, hence its name.  It is very rich in iron, and its leaves have a pleasant mild taste. I have tasted them, so I agree.

Copperleaf or Three-seeded Mercury (Acalypha rhomboidea) grows like a weed in untended areas, although it is a plant that is native to these parts of North America.  It's not an unattractive plant, especially in autumn, when its leaves and bracts turn a lovely copper color, hence its Copperleaf common name.  I happen to love it for its distinctive floral bracts that are shaped like the wings on the heels of the Roman god Mercury, and its tiny bundles of three ball-shaped seeds.  Hence the common name, Three-seeded Mercury.  Its genus name, Acalypha, comes from the Greek word for nettles.  The plant's appearance does somewhat resemble nettles, which is why the great Swedish botantist Linneaus assigned it this name.  (Hmmm . . . .  Why, then, did Linnaeus give the name Urtica to the nettles genus?  Oh yes!  He needed a Latin, not a Greek word, and the Latin word urure, meaning "to burn," seemed a good choice for those stinging plants.  Copperleaf doesn't sting.)

Doorweed (Polygonum aviculare) gets its common name for its propensity to grow in doorways, where it seems to be happiest the more it gets trod upon. Its small, sprawling green leaves are actually quite attractive, and for years I thought it never bloomed.  That's because its flowers are so small I could hardly see them with my naked eyes.  But the macro lens on my camera could, and presented me with this image of a surprisingly pretty green-centered white miniature flower. Wikipedia claims it is native to North America, although my Newcomb's Wildflower Guide gives it an asterisk, meaning it is not. Wikipedia states it is also native to Eurasia, and that the Vietnamese use it in soup and hot pot.

Dwarf Snapdragon (Chaenorhinum minus) is another flower that it takes a sharp eye to see.  But I think it's certainly worth the effort, such a wee, pretty thing it is!  This dainty little flower grows in what look like the most inhospitable places one could imagine, like the littered dirt between railroad tracks or the thin crack between a brick wall and the sidewalk, which is where I took this photo.  Except for the fact that this is an introduced species, I couldn't find any lore about this plant on computer sites.  I wonder if it gets overlooked because it is just so small.

Groundsel (Senecio vulgaris) grows along a sidewalk in my neighborhood, but it often gets weeded out by a zealous groundskeeper before it blooms.  Happily, I got there first, this year.  Not that its blooms are all that much to see.  They never open any wider than this, until they go to seed and explode into silken puffs of down.  These tight little blooms seem to be enough, however, for the many insects I see visiting the little bit of yellow that protrudes above its green bracts.

Pineapple Weed (Matricaria discoidea) is another little flower that seems to prefer the poorest, most compacted soils, and it often hides among taller weeds.  I'm always happy to find it, because I love to pinch its blooms and breathe in its sweet scent that does smell just like pineapple.  I have read you can make a nice-tasting tea from the leaves, especially if you pick them before the plant blooms and turns a bit bitter.  Again, my Newcomb's and Wikipedia disagree on its native status, with Wikipedia claiming this plant is native to North America and Northeast Asia.  Native or not, it grows all over the U.S., including the hard-packed dirt of a street corner in downtown Saratoga Springs.

Purslane (Portulaca oleracea) often gets weeded out of many vegetable gardens, which is pretty ironic, considering it is one of the most nutritious plants that grows there, loaded with Omega-3 fatty acids, an unusual attribute for a green-leaved plant.  It also tastes pretty good, if you like your veggies a bit on the sour side.  I snip a few raw leaves into my French potato salad to give it a bit of a lemony edge.  Anyway, it probably does grow best in the soft, fertile, well-irrigated soil of a garden, but it also seems quite happy sprawling out of the bone-dry cracks in the sidewalk.  Is it native or introduced?  Well, if it's introduced, it's quite a mystery who brought it to North America in the pre-Columbian era.  Scientists suggest it was already being eaten by the native people of North America when the first Europeans arrived on these shores.

Purslane Speedwell (Veronica peregrina) is another plant I had to get to fast before it got weeded out of a planter in front of my church.  Why the heck would anyone prefer boring mulch and ho-hum Petunias to this pretty thing, with its glossy, rather succulent leaves and miniature white flowers?  Maybe the flowers are just TOO miniature for most folks to appreciate them. I think, though,  it should be shown a little more respect, especially since it IS a native wildflower of North America.

Rabbits'-foot Clover (Trifolium arvense) looks just like its name suggests: soft and round and fluffy.  It's even the color of wild bunny fur, a brownish-gray touched with white.  As in the case of most of our clovers, this species was introduced from Europe, and like most other legumes, it fixes nitrogen in the soil, making it valuable as a green fertilizer for soils of low fertility.  The fact that it can create its own nutrients explains how it can grow in soils as sterile as the edge of the parking lot where I found this pretty patch.

Scarlet Pimpernel (Lysimachia arvensis) used to grow from a sidewalk crack in front of a downtown Saratoga hotel.  It doesn't anymore.  The hotel is being renovated, and a fancy new landscaped garden has eliminated all the little sidewalk weeds that I used to treasure there.  I'm including it here because I miss seeing it so.  I haven't discovered it growing anywhere else, and I'm sad I never got the chance to witness how it got its other common name of Poor Man's Weatherglass.  Supposedly, it closes up when the barometric pressure drops, and thus it could predict a coming storm.  I'm glad its bloom was wide open when I took this picture, capturing all the amazing colors this little introduced weed exhibits in its flower.

Spotted Spurge (Euphorbia maculata).  Even though this is one of our native plants, it is one of the weediest of sidewalk weeds, spreading across any patch of barren dry dirt it can find.  It clings as close to this dirt as it can, rapidly carpeting the area, which makes it a useful space-saver for preventing alien invasive species from moving in.   Sometimes its leaves are decorated with a dark spot, hence the reason for its specific epithet "maculata,"  meaning "spotted." I happen to think it's rather a pretty plant, especially when it blooms with these tiny four-petaled flowers.  Granted, the flowers are not very visible from a standing height.  Sometimes passers-by wonder what I am doing crouching down there, trying to get a better view of what's growing in the dirt.

Wormseed Mustard (Erysimum cheiranthoides) usually prefers much richer soils than can be found in sidewalk cracks.  That's probably why this particular plant was so small, instead of the two- or three-foot high plant it usually is.  Yet, small as it is, it still produced its sunny-yellow, four-petaled flowers that will later yield the tiny seeds that give this mustard its common name.  I doubt that these seeds are used this way anymore, but once upon a time they were used to expel worms in the digestive tract.

This fact about the origin of Wormseed Mustard's name was something I learned just today, thanks to my taking a walk around town to visit the sidewalk weeds. (And also, of course, thanks to Wikipedia!) See?  I didn't have to go out to that island in Lake Champlain or up that mountain in the Adirondacks to see all kinds of amazing plants and learn some new things about them.   I just had to look around. Or look down.