Description and phylogenetic position of a new species of Nematanthus (Gesneriaceae) from Bahia, Brazil

Nematanthus exsertus Chautems, a new species of Gesneriaceae from the state of Bahia in Brazil, is described. It is easily distinguished from other Nematanthus Schrad. species by its pendent resupinate flowers with funnel-shaped and laterally compressed corolla combined with striking exserted stamens and style. According to the phylogenetic analyses based on nuclear and plastid DNA sequences, this species belongs to a clade including the morphologically distinct Nematanthus monanthos (Vell.) Chautems and four other species with a similar flower morphology but lacking exserted stamen and style. Field photographs accompany the description. The new species is known from one locality in the municipality of Wenceslau Guimarães in the southern part of Bahia state within the “região cacaueira” [cocoa producing area]. The new species is assigned a preliminary assessment of “Vulnerable” using the IUCN Red List Categories and Criteria.