AN UNUSUAL NEW SPECIES OF CHUSQUEA (POACEAE, BAMBUSOIDEAE) FROM MEXICO

Chusquea perotensis is described from Volcan Cofre de Perote. Although its spikelets are typical of Chusquea, this species is anomalous in h aving the internodes hollow with well defined cavities. Based on molec ular and morphological data, C. perotensis is classified within Chusqu ea sect. Swallenochloa, and is considered a sister species of C. bilim ekii, also from Mexico. Both species are rare and probably threatened in their fragile montane habitats. Keys, based on vegetative only and vegetative and flowering characters, to the species of Chusquea sect. Swallenochloa in Central America and Mexico are provided.