a1 Bolus Herbarium, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
Rhytidocaulon P.R.O. Bally is reviewed. The relationships with other genera are discussed in the light of the character assessment carried out and it is suggested that it is closest to Caralluma R. Br. subg. Caralluma and Echidnopsis Hook. f. Descriptions of the genus and the eight known species are provided.
(Received July 14 1998)
(Accepted February 01 1999)