Epiphyte angiosperms of the priority terrestrial region of Cerros Negro-Yucaño, Oaxaca, Mexico

Sumario: The knowledge on richness and distribution of epiphytic vascular plants still incomplete in many areas of Mexico. An example is the terrestrial priority region (RTP) Cerros Negro-Yucaño which is located in the Northwest portion of Oaxaca and belongs to the Mixteca Alta Region (Ñuu Savi Sukun, Ñuu Vixi). Based on herbarium material reviews of 12 Mexican institutional collections and the collects of specimens in some localities, mainly covered by oak forest, in 17 of the 18 municipalities included in the RTP, we compiled a list of epiphytic angiosperms. The presence of 40 species, distributed in 13 genera and five families was recorded; 28 taxa are endemic to Mexico and three of them are only known from Oaxaca. The genera Tillandsia (18 spp.) and Peperomia (4) were the best represented genera in the area. Oak forest was the type of vegetation in which the most of the epiphytes were found (32 spp.), and also the altitudinal range between 1 900 and 2 100 m (19 spp.). Flowering plants of Artorima erubescens, Laelia albida, L. furfuracea, and Prosthechea karwinskii are used by the local people as ornamentals during the religious celebrations of Día de Muertos and Semana Santa. This human impact might be a threat to the wild populations of these species in the future.