Published online by Cambridge University Press: 11 May 2012
The genus Malacomeles (Decne.) G. N. Jones (Rosaceae subtribe Pyrinae) represents several fruit shrubs, which is mainly distributed in North and Central America, from southern USA to Honduras and Guatemala, although the main distribution of this genus is in Mexico. Five species of the genus Malacomeles have been reported to exist in Mexico. Malacomeles is widely distributed in several mountainous ranges in Mexico, although it is unknown where most of the diversity of the Malacomeles genus is located in the country. The aim of this biogeographic study was to determine the areas of highest diversity of the genus Malacomeles in Mexico based on species richness and diversity indices in order to identify the best regions of Mexico to collect germplasm. The results indicated that most of the diversity of the genus Malacomeles is concentrated in northeast Mexico, mainly in the biogeographic province of Sierra Madre Oriental. In this province, the highest values on three biodiversity indices were found. Thus, this area can be considered as the priority area to collect the germplasm of Malacomeles. M. denticulata is the predominant and the most interesting species in Mexico from the viewpoint of collecting plant genetic resources; this species is mainly distributed in the provinces of Trans-Mexican Volcanic Axis, Mexican Plateau and Sierra Madre del Sur, where secondary priority areas to collect germplasm are located.