Background:

Seasonally dry tropical forests of Mexico include over three thousand species of vascular plants. The Sierra del Abra Tanchipa Biosphere Reserve represents a link for this kind of forests in northern Mexico.

Question:

What is the composition and richness of vascular plants in the Sierra del Abra Tanchipa Biosphere Reserve, its growth forms, endemism, uses, and conservation status?

Study site and research period:

Sierra del Abra Tanchipa Biosphere Reserve, San Luis Potosi, Mexico, between December 2012 to January 2018.

Methods:

Botanical collections were carried out in a gradient from 100 to 700 m asl. Data for habitat, phenology, growth form, common names and uses were recorded.

Results:

89 families, 305 genera and 427 species of vascular plants were recorded. The richest families were Fabaceae, Orchidaceae, Poaceae, Asteraceae, and Euphorbiaceae. The area includes 46 endemic species to Mexico, and eight in some risk category according to NOM-059-SEMARNAT-2010. Among the 116 useful and/or toxic species stand out those used as ornamental, for construction purposes, as food and medicine.

Conclusions:

Species richness in the area is similar to those of other regions with seasonally dry tropical forests of Mexico. The good state of conservation within the reserve, its connection with ecosystems to the North, as well as the presence of endemic species and in some risk category, highlight its importance for conservation of these ecosystems in Mexico.