Friday, October 26, 2012

Phenology for 10/26/12: Purple Violet, Galinsoga

An unusually long, warm, wet summer has produced second generations of some spring flowers this autumn. This afternoon, looking at a well-mown lawn, I noticed the truth of the observation that the non-native flowering grass called lady's-thumb will bloom at whatever height you want. This lawn has been kept below four inches, and ladies'-thumbs were creeping along the ground, making little puddles of bright pink in the grass...that clashed amusingly with the orange and brown leaves waiting to be raked up.

Grandma Bonnie Peters has purple violets in the cracks of her driveway. In spring, she says, she considers them weeds and digs them up so they don't help the cracks grow, but in October she found herself showing off the out-of-season blooms.

While cutting back the spent goldenrod in the front yard, I noticed a new wildflower, smaller than the goldenrod, but more persistent. The yellow centers of the tiny flowers are more conspicuous than the white petals. The flowers are shaped like asters, only instead of having a full round of petals, each flower has five little clusters of three petals. I looked it up in Peterson's Field Guide and learned that it's officially known as galinsoga. Having a name, I could look it up online and find this lovely photo-rich fact sheet:

http://ww w.ppws. vt.edu/s cott/weed_id/ga lci.htm

Online, I learned more about the three very similar species, Galinsoga ciliata, Galinsoga parviflora, and Tridax procumbens. (The Galinsogas have been classified in the genus Tridax in the past.) Which species do I have? I don't know. Peterson's mentions only in passing that there are different, similar species. Ciliata is the most common in southwestern Virginia, according to Virginia Tech, but ciliata means hairy. My plants don't look especially hairy. Parviflora is rare. Parviflora means small flowers; my plants have very small flowers. Procumbens means apt to sprawl along the ground instead of standing straight up like "gallant soldiers," the quaintly garbled British name for Galinsoga. A web site called "eattheweeds.com" offers the confusing information that Galinsogas stand up while Tridax procumbens sprawls, but the photo sites make it clear that, as these flowers grow, all species produce stalks that stand straight up and stalks that sprawl. Mine mostly stand up...as in some of those photos of procumbens. For positive identification...well, on average the seeds differ in size...by half-millimeters.

Does it matter? Well, Galinsoga is considered edible, while Tridax is medicinal. Galinsoga is not considered a noxious weed, and Tridax is. I wasn't planning to eat my flowers, but if any readers out there recognize this plant and want to try it in a salad, they may want to consult the local extension office for positive identification.

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