365 Urban Species. #160: Black Swallow-wort

[urbpan]

Location: Price Road, Allston.

Urban species #160: Black swallow-wort Cynanchum nigrum

Tiny star-shaped flowers , so dark purply-brown they look black, are the primary charm of this weed. Later in the season it develops pods that release seeds that float on silken parachutes (similar to, but more restrained than, cottonwood). It twines up chain-link, putting glossy dark green green foliage on ugly fences. Its attractiveness cause it to be introduced to North America as an ornamental. Unfortunately, there is little else that is positive about this plant, at least as it exists outside of its native range of Eastern Europe.

It is strongly invasive, and has several deleterious effects. Like other members of the milkweed family, it is poisonous. So when it crawls in among crops or pasture fields, it makes mechanical harvesting impossible, and whole pastures unusable by livestock. When it invades grasslands, there is a population drop among birds that nest in such areas. Monarch butterflies recognize it as a milkweed, and lay their eggs on it, but their larva are unable to feed on it, and starve. It joins garlic mustard and Japanese knotweed on the "least wanted" list, for New England native plants enthusiasts.

Comments

[phlogiston-5.livejournal.com]

Although its not related, the shape and size of the flowers reminded me of Dodder. Do you have that growing around the ponds up there?

[sin-agua.livejournal.com]

Such a shame about the Monarchs. :(

[larksdream]

The hatred! The hatred!

Swallowwort is the bane of my gardening existence. It will not die. If you pull it but don't dig out the whole root, it resprouts from broken-off pieces left in the ground. Roundup, a relatively benign herbicide, doesn't even faze it. Investigating online revealed that it is susceptible to the active ingredient in Ortho Brush-B-Gon. I hate using sprays-- except for my battle with swallowwort I have an organic garden-- but it was that or have the entire garden eaten by swallowwort. So I spot-sprayed the worst stands, including places like along the fenceline where it's impossible to pull up all of it. Die, swallowwort, die. I hate you.

Not Post-Relevant

[zipotle.livejournal.com]

I thought of you a lot as I watched these videos. If he were in your monkey cages (if you have any) I bet he'd have a more interesting diet. You could have frozen his kibble into ice cubes and stuffed them into toilet paper rolls!

http://www.youtube.com/profile_videos?user=angrymandotca

[artemii.livejournal.com]

there is a once-was-a-garden down the street that is being absolutely SMOTHERED by this stuff.

i don't know if you remember my old icon with the ants and the little tufty bugs and the aphids, but, that was on a black swallowwort plant. the ants were defending the honeydew-producing aphids and, as far as i could tell, the bugs with tufty butts (some kind of mealybug maybe?--i couldn't find them in any guide books/sites) seemed to be unrelated to the rest of the melee. i wonder if the aphids that feed so prodigously on common milkweed also eat black swallowwort? or perhaps it's a different aphid species altogether...