Sendangusa Bidens frondosa - "Plant-Watcher's bane" The plant I wasn't looking for...

Government Warning Look, "Plant-Watcher's Bane" isn't a real name, OK? I just made it up. (I also realised that I wasn't 105% clear on what "bane" means, so I looked it up in the Shorter Oxford. Basically it was originally "poison", as in "dog's-bane", supposedly poisonous to dogs. The more general meaning of "that which causes ruin or woe" was acquired later.)

This is a straggling nondescript plant. In about September it produces straggly and unspectacular little yellow flowers. However, in a month or so it decides to bring attention to itself - come back from photographing any other plants, or just from a bicycle ride, and the seeds cover every bit of exposed fabric. They have tenacious hooks, and really are a nuisance to get rid of.

From my Japanese plant books I can be confident of identifying this as one of the sendangusa species; judging by the seed photograph (see link below), I am fairly confident it is amerika sendangusa, that is, the American variety, Bidens frondosa. (I don't remember a similar plant from England, by the way.)

The plant in operation - November (800x600 image)

Links

In English America Coweeta - mysterious name, but it's something to do with "Long-term ecological research", and it's on the University of Georgia's server. Useful list of names includes following: Bidens frondosa = "Beggar's ticks" Bidens bipinnata = "Spanish needles"

In Japanese List of weeds - a Japanese government site, belonging to the National Grassland Research Institute. The description of Bidens frondosa is here, but this link includes Japanese characters in the "bookmark" tag, and may not work depending on your setup. This includes photographs both of the plants and the seeds. If you can't read Japanese, you can search for the scientific name, then click the following links. It was the photo of the seed which convinced me that my problem is probably frondosa, because of the two-pronged fork arrangement at the business end.