Flaveria trinervia

Flaveria trinervia is a species of flowering plant in the aster family known by the common names clustered yellowtops, speedyweed, and yellow twinstem. It is native to parts of the Americas, including the southeastern and southwestern United States (Florida, Texas, Arizona, New Mexico), most of Mexico, Belize, 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.