One of my former undergraduate students is Carrie Hadden, pictured here. She distinguished herself within our Department of Biological Sciences by winning the “Outstanding Biology Senior” award a couple of years ago. I’m very happy to have had her as a student: She will make a fine botanist.
The other day we all walked up Main Street to find some lunch, and on the way back to campus saw an assortment of colorful weeds popping up all over the place. Low hop clover has yellow flower, toadflax has purple ones, and crimson clover’s blooms are a handsome red.
Then Carrie picked up a more obscure, less colorful (well, I guess green is a good color) plant growing along the sidewalk, and began tossing it around. The plant will readily stick to your clothing, and of course we all ended up “wearing” some. There we were, grown people out in public, flinging weeds on each other.
Our mystery plant is common all over the United States as a weed. It is a member of a botanical family (the “Rubiaceae”), some members of which are important economically, giving us coffee and quinine, among other things.
This peculiar little herb comes up vigorously in the spring, forming bright green, tender mats of vegetation, often in disturbed places. It is blooming now in our area, and easy to find in vacant lots, roadsides and field edges.
The flimsy stems are slender, and square in cross-section, and quite angular. Equipped thus with weak stems, this plant is generally unable to grow upright, so it flops itself around, commonly sprawling upon other vegetation and forming airish patches.
Six or eight narrow, strap-shaped leaves will be clustered together up and down the stem, forming whorls. The flowers are tiny, each with four white petals. The ovary is inferior, and if you look closely, below the petals, you’ll see it: Green and round.
The most interesting thing about this herb, though, is that all parts of it, especially the angles of the stems, are covered with sharp, backward-pointed bristles. These tiny hooks make it very easy for the plant to snag itself onto passing things, cleaving readily onto fur, feathers, socks, sneakers, trousers legs or even skin (especially hairy skin). These little barbs, present by the thousands, thus act as a natural sort of Velcro, and it makes sense that the plant can spread itself around by this feature.
Carrie, the clever botanist, likes to call it “Velcro plant,” but it also goes by many other names. It (and its near relatives) has been used to stuff mattresses, and its tiny, dried fruits have been used as a coffee substitute. By the way, the little hooked hairs have an adjective all their own, and as you know by now, botanists love to use special terms. The term for a sharp hair that is strongly bent or hooked is “uncinate.”
Another one of our spring weeds, it makes quite a show for a few weeks, and then all the plants dry up and disappear by early summer. You have plenty of time to try some on.
John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences. As a public service, the herbarium offers free plant identifications. For more information, visit www.herbarium.org, call 803-777-8196 or email nelson@sc.edu.
Answer: “Cleavers,” “Bedstraw,” Galium aparine