Eriosema triformum (Leguminosae: Papilionoideae), a new unifoliolate species from Guinea, West Africa

Abstract

Eriosema triformum Burgt (Leguminosae: Papilionoideae), a new species from Guinea in West Africa, is described and illustrated. E. triformum is a pyrophytic herb with unifoliolate leaves, from submontane grassland at 1,250 – 1,600 m altitude. The species exhibits three phases during the year: a dormant phase during which only the underground tuber remains; a flowering and fruiting phase during which the plants are erect and 6 – 16 cm high; and a sterile, leafy phase during which the scrambling stems may grow to 60 cm length. E. triformum is only known from a 16 km long part of the Simandou Range, north and south of Pic de Fon. Most nearby mountain ranges in Guinea were visited to search for E. triformum. In 19 other localities, submontane grassland habitat was found; but E. triformum was not found. The IUCN conservation status is assessed as Endangered. A key to the 10 unifoliolate species of Eriosema from Guinea and surroundings is presented.