iPhoneOgraphy – 20 Jan 2016 (Day 20/366)
Bidens is a genus of flowering plants in the aster family, Asteraceae. The common names beggarticks, black jack, burr marigolds, cobbler’s pegs, Spanish needles, stickseeds, tickseeds and tickseed sunflowers refer to the fruits of the plants, most of which are bristly and barbed, with two sharp pappi at the end. The generic name refers to the same character; Bidens comes from the Latin bis (“two”) and dens (“tooth”).
Bidens is distributed throughout the tropical and warm temperate regions of the world. Most species occur in the Americas, Africa, and Polynesia, and there are some in Europe and Asia. Bidens is closely related to the American genus Coreopsis, and the genera are sometimes difficult to tell apart; in addition, neither is monophyletic.
On the Hawaiian Islands, Bidens are called kokoʻolau or koʻokoʻolau.