| Bidens cernua | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Bidens |
| Species: | B. cernua |
| Binomial name | |
| Bidens cernua | |
| Synonyms | |
| |
Bidens cernua is a species of flowering plant in the aster family, Asteraceae. It is commonly called nodding beggarticks or nodding bur-marigold. Bidens cernua is distributed throughout much of Eurasia and North America.


Bidens cernua is an annual species growing roughly 1m tall, with a fibrous root. Stems are rigid and often either simple or beached. Stem leaves are simple, unstalked, and opposite with saw-toothed to almost smooth margins.
It has yellow flowers with 6–8 ray narrowly lance shaped petals around a central disk. The hemispheric heads are solitary at the ends of branches and nod with age.
The achenes are narrowly wedge-shaped and 4-sided, flattened and ribbed. The pappus has 3–4 barbed bristles.
Bidens cernua is distributed throughout much of Eurasia and North America.