Why continue with floristic checklists in Mexico? The case of the Tacaná-Boquerón Priority Terrestrial Region, in the Mexican State of Chiapas

Background: Some regions of Mexico have been relatively well explored floristically and estimates of the vascular plant richness they contain have been obtained. However, there are still regions that require effort to obtain the most appropriate lists of flora possible that consider both systemization of the information and that benefit from recent botanical explorations. Questions: What is the species richness of vascular plants in the Tacaná-Boquerón Priority Terrestrial Region? What proportion of the species are endemic or included in risk categories? Study sites and dates: Tacaná-Boquerón Priority Terrestrial Region, Chiapas State, Mexico. This region is on the Guatemala border and covers an area of 57,400 ha. Between 1920 and 2015. Methods: A database of 14,487 vascular plant records was integrated. Two sources of information were compared: systematization of databases, and recent botanic expeditions. Results: We found 2,485 native species belonging to 185 families. Both data sources were complementary in order to obtain a more complete floristic checklist (systematization of database: 1,774 spp., recent botanic expeditions: 1,514 spp.). As novelties, we found three new species and seven new reports for Mexico. Approximately 14 % of the species documented are included in risk categories or are endemic to the study site. Conclusions: Our checklist is one of the largest in the region (Mexico and Central America) in terms of species count. Our study shows the importance of conducting botanical explorations to complement the information on vascular plant richness in relatively well-explored areas of Mexico.