Riqueza de las familias Agavaceae y Nolinaceae en México

Abstract

We show the distribution of the Agavaceae and Nolinaceae families in the Americas and in Mexico. For Mexico we determined the existence of 402 taxa of which 342 belong to the genera Agave, Beschorneria, Furcraea, Hesperaloii, Manfreda, Polianthes, Prochnyanthes and Yucca in the Agavaceae family, while 60 are from the genera Beaucarnea, Calibanus, Dasylirion and Nolina from the Nolinaceae family. We also show an updated list of the species from both families arranged alphabetically. For each taxon we describe their distribution by state and by floristic provinces. The richest states are Oaxaca with 63 taxa, Durango with 52, Puebla with 50, San Luis Potosí and Sonora with 47 and Chihuahua with 45. The floristic provinces with higher number of taxa are: The Meridional Sierras, the Sierra Madre Occidental and the Central Mexico Highlands. At the moment,' for Mexico, five regional floras have been finished that study the Agavaceae and Nolinaceae at different levels. The genera Agave, Beaucarnea, Beschorneria, Manfreda and Prochnyan.thes have had recent taxonomic treatments; others like Dasylirion, Furcraea and Polianthes are in different stages of development, while Calibanus, Hesperaloii, Nolina, Yucca and several groups of Agave require an update. We review data on the representation of the taxa in two of the main herbaria in México (ENCB and MEXU), which comprise 220 species, backed by 3,593 vouchers, with an average of 16.3 vouchers per taxon. Nevertheless it is necessary to increase the collection for herbarium and botanical gardens, to not only to back up floristic and taxonomic research, but also to support research in ecology, ethnobotany, conservation biology, etc. These actions will allow us to have a better knowledge of the biology of the Agavaceae and Nolinaceae.