Two endemic new species of Begonia (Begoniaceae) from Palawan, Philippines

Abstract

On recent expeditions, two endemic new species of Begonia sect. Baryandra, Begonia obscuribracteata Y.P.Ang, Cabanillas & M.N.Tamayo and Begonia tandikan Pranada, L.M.Camangeg, Cabanillas & Y.P.Ang, were discovered and are hereby described and illustrated. Begonia obscuribracteata is similar to B. cabanillasii Y.P.Ang et al. in having suborbicular leaves that are adaxially hairy, five conspicuous wings on the ovary, and tepals that are hairy on the outside. However, it can be easily distinguished by features of its leaves, stipules, and bracts. A key to similar Begonia species with a conspicuous 5-winged ovary is provided. Begonia tandikan morphologically resembles B. beijnenii Y.P.Ang et al. but differs by having a broadly ovate (vs subrhomboid) lamina with a villous (vs glabrous) upper surface, shorter and wider stipules with aristate (vs cuspidate) apices, and minutely pilose (vs glabrous) bracts. Following IUCN guidelines, Begonia obscuribracteata is assessed as Endangered (EN) and Begonia tandikan as Critically Endangered (CR).