A new nothospecies of Prosthechea (Orchidaceae: Laeliinae) from the Diamantina Plateau, Minas Gerais, Brazil

Based on morphological evidence found in some specimens recently collected in the Diamantina Plateau region, Minas Gerais State, Brazil, a new natural hybrid between Prosthechea calamaria and P. faresiana is described and illustrated as P. ×riopretensis. Both putative parental species are known for the region and their flowering period overlaps. The new nothospecies carries most of the morphological features of P. calamaria, such as short plants (≤ 19 cm height) and inflorescences (≤ 7 cm long), and flowers with a small ovate lip (≤ 1 cm long), but the floral color pattern are remarkably like P. faresiana – sepals and petals covered by longitudinal vinaceous stripes. In addition to a digital composite plate of the taxonomic novelty, further images and a distribution map of the new nothospecies and its putative parents are provided, as well as notes on morphology, phenology, and ecology.