Background:

Mountain ecosystems shelter high levels of biodiversity. The microbasin of the Los Chivos Canyon is an important source of biodiversity of the Sierra Madre Oriental, and a refuge for mountain ecosystems in the region.

Question:

What is the composition and richness of vascular plants in the microbasin of the Los Chivos Canyon, growth forms, distribution of vegetation types, endemics, and conservation status.

Study site and research period:

The microbasin of the Los Chivos Canyon, Alvarez mountain range, San Luis Potosi, Mexico, between February 2016 and June 2019.

Methods:

Botanical collections were carried out in each vegetation type, along a gradient from 1,437 to 2,702 m asl. Data for habitat, phenology, and growth form were recorded.

Results:

104 families, 327 genera, and 545 species of vascular plants were recorded. The richest families are Asteraceae, Fabaceae, Orchidaceae, Poaceae, and Cactaceae. The area includes 181 species endemic to Mexico and 24 to San Luis Potosí and adjacent regions. Eleven species are included in the NOM-059-SEMARNAT-201045, 84 in the IUCN Redlist (six in a threatened category), and 45 in the CITES. There are six new records for the state.

Conclusions:

The species richness in the area is relatively higher than other areas having mountain ecosystems in the region. Its conservation status, as well as its proximity to natural protected areas, its endemism, and the proportion of species with some risk category, highlight the relevance of the area as a priority for the conservation of this ecosystems in Mexico.