Dos especies nuevas de Perymenium (Compositae-Heliantheae) del centro de México

perymenium ibarrarum and p. moctezumae are described as new and illustrated. the first one resembles and is possibly related to p. hintonii mcvaugh; the second seems to be related to p. tamaulipense b. l. turner and to p. sotoarenasii rzed. & calderón. both are only known from the type collections.