Distribution and occurrence of Ascomycetes in Mexico

Mexico, with a land surface area of 1.97 M sq. km., has a topography that varies from high plains in the north, to tall volcanic mountains in the south-central region, to lowlands in the south, as well as extensive coastlines. Southern Mexico is the area where the temperate climate of North America unites with the tropical climate of Central and South America, resulting in a highly diverse ecosystem that supports an abundant biota, including ascomycetes. The mycological literature was reviewed for records of ascomycetes from Mexico, which yielded 1,331 species plus 24 varieties, for a total of 1,355 identified taxa of ascomycetes known from the country. Approximately 35% of these are lichenized. The anamorphic ascomycetes were not included in this compilation. Taxonomically, these ascomycetes are distributed among 414 genera belonging to 41 orders and 126 families. The Xylariales is the best studied group, with 100 species of  Xylaria  and 48 species of  Hypoxylon  recorded .  Other common genera are  Parmotrema  (36),  Laboulbenia  (32),  Cladonia  (30),  Podospora  (29),  Heterodermia  (27),  Meliola  (22),  Sporormiella  (21) and Hypotrachyna  (21).  Peziza  and  Morchella  are the most common discomycetes, with 14 and 13 species, respectively. With regard to geographical distribution, the most explored areas in the country are the State of Veracruz, the State of Mexico, the State of Oaxaca, and the State of Chiapas located in the central-southeast region of the country, and the least studied areas are the State of Nayarit, the State of Aguascalientes, and the Peninsula of Baja California.