Taxonomic revision of Zamia in Mega-Mexico

Abstract

The genus Zamia is revised for Mega-Mexico, with 22 species recognized and described. The study presents a taxonomic clarification for the genus in Mesoamerica, a contribution that provides the foundation for a future monograph for Zamia in the Neotropics. The largest proportion of species richness and endemism for the genus is concentrated in southeastern Mexico, among the states of Chiapas, Oaxaca, Tabasco, and Veracruz, an area that is considered highly diverse in floristic terms. Distribution maps and a key to species are also provided, as well as complete descriptions of the specimens examined, including information on nomenclatural types, habitats, synonymies, and etymologies. A lectotype is designated for Zamia loddigesii, and neotypes for Z. galeottii, Z. leiboldii var. angustifolia, and Z. variegata. Zamia spartea is illustrated for the first time, and chromosome numbers for Z. herrerae are reported and illustrated. Finally, scanning electron micrographs of leaflet trichome character states are presented, along with a discussion of their systematic implications within the group.