We describe Croton calcareus Riina & Mateo-Ram. sp. nov., a new species in Croton section Cyclostigma (dragon’s blood trees) from the state of Chiapas (Mexico). This species is a small tree growing in dry forest on calcareous substrates. Both morphological and molecular data support C. calcareus sp. nov. as a new species closely related to C. redolens, another dry forest taxon from northern Venezuela. We provide illustrations, a distribution map and suggestions for species conservation status. The new species along with Croton draco are the only known representatives of C. section Cyclostigma occurring in Mexico.
Croton section Cyclostigma, dry forest, Euphorbiaceae, Neotropics, phylogeny