Verbesina encelioides

Native to parts of the United States and Mexico, the Caribbean, and western and southern South America, this annual herb belongs to the daisy family and grows about 2 to 4 feet tall. Hairy, branching stems carry toothed leaves with whitish undersides. Yellow flower heads have broad outer florets with notched tips surrounding many small tubular florets. The dry fruits from the central florets have broad wings. It grows rapidly on disturbed ground and can poison sheep and cattle. It has naturalized in Australia and is invasive on Midway Atoll, United States, where dense stands reduce nesting space and airflow for seabirds. Photographed in Colombia.