New records to Odontadenia hypoglauca (Apocynaceae) in Brazil

Odontadenia hypoglauca is a species of Apocynaceae previously recorded only in the Cerrado and ombrophilous forest vegetation types, in the Cerrado and Amazon and Atlantic Forest domains, respectively, in Brazil and Bolivia. In this paper, we show new records of the species for the states of Maranhão, Piauí and Tocantins, thus expanding its known distribution in Brazil to the caatinga and seasonal deciduous forest vegetation types, in the Caatinga and Atlantic Forest domains. In the state of Piauí in particular, this is also the first record of the genus Odontadenia. In addition to reporting these new records, we provide a description for the species, photographs, geographic distribution, taxonomic comments, conservation status, map, and an identification key for the species of Odontadenia that occur in the aforementioned states and other morphologically related species.