Revisão taxonômica do gênero Varronia P. Browne (Cordiaceae, Boraginales) para o Brasil

Abstract

The genus Varronia, after several modifications, was reestablished at the beginning of the 21st century and is composed of about 125 species. Exclusively Neotropical, Varronia is well represented in Brazil, mainly in the areas of the Caatinga and Cerrado, with endemic and economically important species. Due the controversial taxonomic-nomenclatural history, recent conceptual stability at the generic level, and its representativeness in Brazilian territory, is important a recent revision of the genus in order to improve the taxonomic, nomenclatural and distribution of its species. Thus, the present carried out the taxonomic revision of the genus Varronia from Brazil, one of its main centers of diversity. For that, specimens of Varronia and Cordia were examined in Brazilian and international herbaria beyond collection expeditions carried out. The results of the revisional study pointed to names of Brazilian and foreign species in need of nomenclatural updating and / or typification, new species and new records in Brazilian states. All results obtained are presented in the form of scientific articles containing: (1) The taxonomic revision of Varronia for Brazil, where thirty-five species were recognized, of which 21 are endemic. Eight new synonyms and eleven typifications for valid names are suggested. Descriptions, nomenclatural updates, identification key, illustrations and photographs, distribution data and morphological comments are provided; (2) Two manuscripts with new combinations for species of the genus, a new synonym, a neotype and lectotypification; (3) Two new species are proposed, one of which has already been published, together a new record for Brazil; (4) The rediscovery, from collections of herbaria, of a species known only by type, and the proposal for lectotyping a related name; (5) The anatomical data based on the analyses of the leaf blade corroborate to assist in the better demilitation of some species of the genus.