Starting from fresh studies on D. abyssinicum and D. schimperi in Ethiopia, the members of the genus Delosperma in north east Africa and south west Arabia are re-investigated, resulting in the recognition of seven distinct groups, one of which is described as a new species: D. sawdahense H.E.K.Hartmann spec. nov. from Saudi Arabia. Another group of populations from Eritrea cannot be assessed at present, due to lack of material. A key to the six named taxa is given, and some suggestions for further studies into the origin and evolution of the group are presented.