Two new species of Rhynchospora (Cyperaceae) from Bahia, Brazil, and new combinations in Rhynchospora section Pleurostachys

Recent molecular phylogenies have demonstrated that Pleurostachys (Cyperaceae) should be recognized as a section within Rhynchospora. Here all accepted species of Pleurostachys are transferred to Rhynchospora sect. Pleurostachys, five new combinations are made, and one new name provided. Rhynchospora austrobahiensis and R. contraligularis are described as new species endemic to the Atlantic forest of southern Bahia, Brazil. They are distinct from all other species of sect. Pleurostachys by having spikelets that are never clustered and basal leaves over 1 cm wide. The summit of the inner band of the leaf sheath on R. austrobahiensis is concave to triangular while that of R. contraligularis is arched with a distinct, chartaceous contraligule. Both species are illustrated and compared to other species of Rhynchospora sect. Pleurostachys.