Horticulture/Bidens frondosa

Devil's beggartick (Bidens frondosa) is an annual herb in the family Asteraceae, native to North America.

This plant is known by a variety of different names, including Bur Marigold, Devil's Bootjack, Devil's pitchfork, Pitchfork Weed, and Sticktight.

The sticky seeds make this plant a nuisance for pet and livestock owners, and it is generally seen as a weed.

Description
It looks similar to a Dahlia plant, up to 2 m tall, usually with reddish stems. Its flowers are yellow, produced in early autumn, followed by numerous seeds with hooked barbs that attach onto passing animals' fur or clothing or sometimes even skin which allow the seeds to be dispersed widely.

Uses
During flowering, the plant is an autumn nectar source, though other plants should be used instead because of the seed problems.