They are herbaceous plants or subshrubs with annual, biennial, or perennial life cycles.[5] The flowerheads are composed of numerous yellow disc florets (usually between 100–200) and from zero to sixty or more yellow or orange ray florets.[5]Grindelia squarrosa, a plant with bright yellow flowers indigenous to much of the United States, is commonly called curlycup gumweed. Grindelia robusta, found in the western states, is a coastal scrub bush that is reputed to have several medicinal uses. Hairy gumweed, Grindelia cuneifolia, occurs in brackish coastal marshes of western North America, such as in some portions of the San Francisco Bay perimeter.[5] The genus is native to South America, Mexico, and western North America, though some species have been introduced and naturalized in eastern North America and the Old World.[5]
^Willdenow, Carl Ludwig von. 1807. Magazin für die Neuesten Entdeckungen in der Gesammten Naturkunde, Gesellschaft Naturforschender Freunde zu Berlin 1(4): 259–261
^"Grindelia". County-level distribution maps from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2013.
^Davidse, G., M. Sousa-Peña, S. Knapp & F. Chiang Cabrera. 2015. Asteraceae. 5(2): ined. In G. Davidse, M. Sousa Sánchez, S. Knapp & F. Chiang Cabrera (eds.) Flora Mesoamericana. Universidad Nacional Autónoma de México, México
^Pruski, J.F. & G. Sancho. 2004. Asteraceae or Compositae (Aster or Sunflower Family). 33–39. In N. Smith et al. (eds.) Flowering plants of the Neotropics. Princeton University Press, Princeton.
