Background and Aims:

The study area of La Salada basin is situated in the southern-central area of Colima, characterized by tropical dry forest vegetation on gypseous (74.5%) and calcareous (25.5%) soils. This site was visited by the eminent botanist Rogers McVaugh and is represented in the Flora Novo-Galiciana. However, only a part of his collections has been available for consultation. The objective here is to document the diversity of vascular plants in this site providing evidence which sustains its biological relevance.

Methods:

Revisions of bibliography and material in the herbaria IBUG and MICH were made. Specimens from recent fieldwork were integrated into the list. Additionally, electronic databases (IBdata and GBIF) were reviewed to obtain records of collections in sites of Colima with ecological characteristics similar to the sampled area. The Index of Taxonomic Diversity (IDT) was calculated facilitating comparisons of values for other areas with tropical dry forests.

Key results:

A total of 408 taxa, 248 genera and 78 families of vascular plants of BTC in other gypseous-calcareous soils of Colima were registered. Two appendices are provided: the first with authors´ collections and those in bibliography; and the second with citations of species in other gypseous-calcareous soils in Colima from databases. In the first, 368 taxa (including 16 infraspecific taxa) in 233 genera and 75 families were recorded. The families Fabaceae, Euphorbiaceae, Asteraceae, Malvaceae, Poaceae and Convolvulaceae total 48% of the reported flora. The genera with greatest diversity were Euphorbia (13), Bursera (eight), Ipomoea (seven) and Tillandsia (six). Of the species recorded 39% (144) are endemic to Mexico and this site is the type location for 23 species. The IDT calculated is 330.35 species/ln area.

Conclusions:

The high floristic diversity and endemism of the area with gypseous and calcareous soils, substantiate conservation of these ecosystems which are being impacted in Colima.