| Flaveria trinervia | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Flaveria |
| Species: | F. trinervia |
| Binomial name | |
| Flaveria trinervia (Spreng.) C.Mohr |
|
Flaveria trinervia is a species of flowering plant in the aster family known by the common name clustered yellowtops. It is native to parts of the Americas, including the southeastern and southwestern United States, most of Mexico, and parts of the Caribbean, but it is known in many other places as an introduced species and often a noxious weed, such as in Hawaii. It grows easily in many types of wet habitat, including saline and alkaline soils and highly disturbed habitat. This is an annual herb growing erect and known to exceed two meters in maximum height. The lance-shaped to oval leaves are each up to 15 centimeters long and arranged oppositely in pairs around the stem, their bases sometimes fused together. The edges of the leaves generally have tiny widely-spaced teeth. The inflorescence is a large dense cluster of many flower heads, sometimes over 300 in one cluster. Each flower head is either radiate, bearing one single yellowish ray floret, or discoid, bearing one or two smaller disc florets.
This plant exhibits C4 carbon fixation.