This "sunflower" does not have flower petals. It is one of 20 sunflowers in Florida. Rayless sunflower is frequent in wet flatwoods in the northern counties south to the central peninsula, of Florida and Collier county. It blooms in the summer (Wunderlin, 2003).
Nearly 70 species and varieties of Helianthus are found in the U.S. and Canada. Rayless sunflower is found only in the most southeasterly states (Kartesz, 1999).