About Bidens cernua L.
Bidens cernua L. is an annual plant species that grows to roughly 1 meter in height, and has a fibrous root system. Its stems are rigid, and are most often either unbranched or branched. The stem leaves are simple, unstalked, and arranged oppositely, with margins ranging from saw-toothed to nearly smooth. This species produces yellow flowers, with 6 to 8 narrowly lance-shaped ray petals arranged around a central flower disk. The hemispheric flower heads grow solitarily at the ends of branches, and nod downward as they age. The achenes of Bidens cernua are narrowly wedge-shaped, 4-sided, flattened, and ribbed. Its pappus has 3 to 4 barbed bristles. Bidens cernua is distributed across most of Eurasia and North America.
