A Systematic Study of the Mexican, Central American, and Jamaican Species of the Genus Calea.

Abstract

Calea, a large genus in the Asteraceae, tribe Heliantheae, consists of mostly shrubs that occur throughout the Neotropics. Robinson and Greenman's treatment of the Mexican and Central American species has remained the definitive study of Calea for this area since 1896. Recent studies, including the present one, have greatly modified their earlier treatment. From among the more than 75 names attributed to Calea in Mexico, Central America, and Jamaica, the present study recognizes 18 taxa representing 8 species and 10 varieties. The species recognized in this treatment include C. crassifolia, C. fluviatilis, C. longipedicellata, C. jamaicensis, C. prunifolia, C. ternifolia, C. trichomata, and C. urticifolia. One variety, C. urticifolia var. yucatanensis is described as new. Calea megacephala is excluded from Calea with the recommendation that it be accommodated in the monotypic genus Tonalanthus Brandegee.