Morphological and Molecular Evidence Support Elevating Erythroxylum macrophyllum var. savannarum (Erythroxylaceae) to Specific Status

Abstract

Abstract Erythroxylum macrophyllum is a morphologically variable and widely distributed species complex in Central and South America with several sub-specific taxa and numerous species included in its synonymy. A single variety grows in the Colombo-Venezuelan savanna region which can be distinguished from the rest of the E. macrophyllum complex by the size of leaves, cataphyll and stipule characteristics, and shape of calyx lobes. A molecular phylogeny reconstructed from 519 nuclear genes also reveals that the savanna variety is more closely related to E. acuminatum and E. pauciflorum than E. macrophyllum. This phylogenomic evidence also suggests Erythroxylum sect. Macrocalyx, to which E. macrophyllum belongs, is a polyphyletic taxonomic section. We thus propose elevating this variety to specific status, as Erythroxylum savannarum. We provide an updated taxonomic description, information about its habitat and distribution, and justify its informal IUCN categorization of Near Threatened (NT).