Encelia is a member of the tribe Heliantheae of the Asteraceae. It consists of shrubs (and one geophyte) of arid environments in southwestern North America and western South America. All have n = 18 chromosomes. With the exception of the South American species, all are obligate outcrossers. In cultivation, the species readily form fertile F1 hybrids, F2s, and backcrosses, but in natural areas of sympatry, F2s and backcrosses are absent or rare.
The sister group of Encelia is a clade comprising the sister genera Enceliopsis and Geraea. Enceliopsis species are suffrutescent perennials, and Geraea contains one geophyte and one annual. The three genera are informally called the "Encelia alliance". Flourensia is the outgroup to the alliance.
These pages are intended to provide a reference to the past and current research on this group.
Space for this page is provided by California State Polytechnic University, Pomona. Although it is intended to further the educational mission of the University, the opinions expressed here are those of Curtis Clark, and do not represent official policy of the University.