Senna (Leguminosae-Caesalpinioideae) in Minas Gerais state, Brazil

Abstract Senna comprises about 350 species worldwide, of which 80 species occur in Brazil. This work brings an update taxonomic treatment of Senna species in the state of Minas Gerais, the second most diverse state for the genus, through the morphological analysis of about 2,348 specimens from herbaria and fieldwork. Thirty-six species and 29 varieties were recognized, including 34 native species and 2 cultivated species. Of the 39 species reported in literature for the state, but 4 species were excluded from the list produced. The occurrence of Senna acuruensis was confirmed; S. macranthera var. striata and S. pilifera var. tubata are new records, and S. hirsuta var. acuminata is endemic to Minas Gerais. There are 28 species in the Cerrado, 26 species in the Atlantic Forest and 20 species in the Caatinga. The distribution of Senna pentagonia var. pentagonia is extended to include the Atlantic Forest. Identification keys, descriptions, illustrations, taxonomic comments and geographic distribution are provided for the species and varities.