Stemodia perfoliata (Plantaginaceae): A 200 year old new species from the Caatinga of Minas Gerais, Brazil

A new species of Stemodia (Plantaginaceae) from the Caatinga of northern Minas Gerais, Brazil, is described and illustrated. Stemodia perfoliata was first collected by Auguste de Saint-Hilaire, ca. 200 years ago, and remained unnamed until now. The new species is characterized by the connate-perfoliate leaves, a unique feature in the genus. We provide notes on morphology, geographic distribution and conservation status of S. perfoliata, along with a key to differentiate it from the similar species that occur in Brazil: S. durantifolia, S. hyptoides, S. maritima, S. palustris and S. stricta.