Erythroxylum pyan (Erythroxylaceae), a new species from the Brazilian semiarid region

Based on fieldwork and an extensive analysis of herbarium and type collections, a new species which grows in sedimentary soil in the Brazilian semiarid region, Erythroxylum pyan (Erythroxylaceae), is described here. The new species occurs in areas of hyperxerophilic caatinga in the states of Piaui, Ceara, Rio Grande do Norte, Paraiba, Pernambuco, and Bahia. Erythroxylym pyan resemble E. nummularium, but can be distinguished by having slender branches, foliar stipules non-striated longitudinally, 2-setulose at apex, leaf blades membranous to slightly chartaceous, emarginate to retuse at apex, inflorescences with 1 flower per node, long, slender and erect pedicels, and calyx lobes cuspidate at apex. Additionally, a distribution map and data about its phenology, conservation status, and uses are provide.