BIDENS

genus of weedy herbs in the family Asteraceae, consisting of about 230 species, variously known as bur-marigold, sticktights, beggar-ticks, and tickseed-sunflowers, distributed throughout the world. Some have divided leaves with toothed segments and long ray flowers; others have undivided, lance-shaped leaves and short ray flowers or none at all. All species have yellow disk flowers and fruits with two to four barbed bristles that become attached to animal coats or to human clothing. One species, B. ferulaefolia, is cultivated as a garden ornamental.