The grass family (poaceae) in Coahuila, Mexico: Diversity and distribution

Abstract

We analyzed the species richness of the grass family (Poaceae) in the state of Coahuila, Mexico, evaluating data from herbarium specimens. The evaluation was made by dividing the state into a grid of 20′ x 20′ squares (latitude x longitude), the objective was to identify areas of high species diversity. The herbaria revision documented 319 species of grasses, distributed in eight subfamilies, 19 tribes, and 97 genera. The genera with the highest number of species are Muhlenbergia (32 species), Bouteloua (21), and Eragrostis (18). Seven species are endemic to Northeastern Mexico (Bromus densus, Bouteloua eriostachya, B. johnstonii, Calamagrostis coahuilensis, Festuca coahuilana, F. valdesii, and Poa wendtii) and, 58 species, plus one subspecies and one variety are rare. Because arid areas cover a larger portion of the state, the subfamily Chloridoideae is dominant with 125 species. The subfamily Panicoideae has a record of 87 species and is mainly present in humid regions, while the Pooideae is abundant in the mountain regions of southeast and northwest, and includes 86 species. We evaluated the species richness for each grid square and propose some of these as important areas to carry out future conservation projects.