Two new species of Marsdenia R. Br. (Apocynaceae: Asclepiadoideae)from the semi-arid region of Brazil

摘要

Two endangered new species of Marsdenia R. Br. (Asclepiadoideae, Apocynaceae) from the semi-arid region of Brazil are described and illustrated: M. breviramosa (south-western Bahia) and M. nana (northern Minas Gerais). They are shrubs closely related to M. zehntneri and, like that species, are also associated with calcareous outcrops. The former can be recognised by linear leaves arranged in small, compact shoots and the latter is a subshrub less than 50 cm high whose flowers are unique because of the adaxially villous corolla and long-rostrate gynostegium.