A new Eriosema (Leguminosae Papilionoideae) from Gabon and adjacent Congo.

Background – On-going botanical research in Gabon continues to yield species new to science, in this case a new member of the leguminous genus Eriosema. Material and methods – Normal practices of herbarium taxonomy have been applied; material is present in LBV, MO, and WAG. Key results – A new species, Eriosema batekense Maesen & G.M. Walters, is described and illustrated. The stems of the new species are not as thin as in E. youngii. The tubers are narrow-spindly and straight, vertical in the soil, not napiform as in E. youngii. Another similar species, E. linifolium, is more robust with thicker stems and rootstock. E. batekense occurs on the Batéké Plateaux in Gabon, and has also been collected from the nearby Bafuru Plateau in Congo-Brazzaville. It is restricted to Kalahari sands. The species is assessed to be of Least Concern according to the IUCN criteria