Background:

The state of San Luis Potosi nowadays lacks a precise analysis of the richness and distribution of the family Orchidaceae, as well as its potential areas for exploration.

Question:

What are the genera and species of Orchidaceae in the state of San Luis Potosi, its geographical and ecological distribution, and requirements for exploration and recollect?

Study site and research period:

San Luis Potosi, Mexico, August 2004 to June 2020

Methods:

We consult data bases and herbaria vouchers. We conducted botanical recollections. The potential richness of Orchidaceae was estimated with Jack 1. We analyzed the altitudinal distribution and by type of vegetation. We quantified the similarity between different biomes throughout the Jaccard index and the Ward’s method. The endemism in Mexico and its biogeographic extensions, and risk status of the species was characterized. Throughout the records in municipalities the requirement of exploration was evaluated.

Results:

We documented 70 genera and 152 species. The records of the Orchidaceae in San Luis Potosi represent 84 % of the 182 species estimated. Most of the richness correspond to the cloud forest. Similarity between different biomes is low. We found 84 endemic species to Mexico and biogeographic extensions. Eight species are in some risk status. We suggest continuing the exploration adjacent to Guanajuato, Queretaro, Hidalgo, and Tamaulipas.

Conclusions:

The richness we report here exceeds in 90 % the previously registered and put the family in the fifth place in the state of San Luis Potosi.