New species of Asclepias (Apocynaceae), Baphia (Leguminosae), Cochlospermum (Bixaceae) and Endostemon (Lamiaceae) from the Kalahari sands of Angola and NW Zambia, with one new combination in Vangueria (Rubiaceae)

Four new species are described from central and eastern Angola adjacent NW Zambia. All occur in Kalahari sand savannas rich endemic more widely distributed geoxylic suffrutices. Despite being known very few collections, the conservation status of one these is assessed as Least Concern, grasslands nutrient-poor, remote sparsely populated areas, not threatened with conversion to agriculture. The remaining three treated Data Deficient. In addition, combination provided for Ancylanthos rubiginosus Desf. under Vangueria V. rubiginosa (Desf.) Lantz an illegitimate later homonym. We also make orthographic corrections specific epithets commemorating Ilse von Nolde, a collector who made important collections Quela Malange 1930s.