Chromolaena frustrata

Chromolaena frustrata called Cape Sable false thoroughwort or Cape Sable thoroughwort, is a rare North American species of flowering shrub in the family Asteraceae. It is found only in southern Florida, on the Florida Keys, inside Everglades National Park, and other nearby low-lying areas. It grows on coastal rock outcrops, the edges of hammocks, and other undisturbed sites at elevations less than 10 meters (33 feet) above sea level. Chromolaena frustrata is a perennial herb rarely more than 25 cm (10 inches) tall. Flower heads are produced in groups of 2–6. The heads contain blue or lavender disc florets but no ray florets....read more on Wikipedia.