Dalechampia L. (Euphorbiaceae) in the Brazilian Amazon

A taxonomic treatment of Dalechampia species found in the Brazilian Amazon is presented. The study was based on an analysis of herbarium material (including historical and type collections), specimens collected in the field, and literature. Twenty-three species, distributed in five sections, are recognized. Dalechampia hastata is endemic to the Brazilian Amazon. Among the species surveyed, thirteen species are considered to be Least Concern (LC), and not currently at risk of extinction. Six species (D. attenuistylus, D. brownsbergensis, D. fragrans, D. hastata, D. megacarpa and D. olympiana) are Endangered (EN), three species (D. gentryi, D. heterobractea and D. tenuiramea) are Near Threatened (NT), and D. liesneri is listed with Deficient Data (DD). If we consider the occurrence only in Brazil of three species , the taxa can be designated as Vulnerable (VU). Dalechampia micrantha and D. parvibracteata are lectotypified. The lectotype of D. cissifolia, D. juruana, and D. pernambucensis is clarified. New occurrences are reported for some countries. An identification key, descriptions, taxonomic comments, illustrations, the conservation status, phenological data, and geographic distribution maps are provided.