Rhytidocaulon


Rhytidocaulon is a plant genus in the family Apocynaceae, first described in 1962. It is native to northeastern Africa and the Arabian Peninsula
;Species
  1. Rhytidocaulon paradoxum P.R.O.Bally - Ethiopia
  2. Rhytidocaulon piliferum Lavranos - Somalia
  3. Rhytidocaulon richardianum Lavranos - Somalia
  4. Rhytidocaulon subscandens P.R.O.Bally - Somalia, Ethiopia
  5. Rhytidocaulon tortum M.G.Gilbert - Arabia
;species with undetermined affinities
;Taxonomy
Phylogenetic studies have shown the genus to be monophyletic, and most closely related to the genus Echidnopsis which inhabits the same region. Marginally more distantly related is a sister branch comprising the genus Pseudolithos and the widespread Caralluma stapeliads of North Africa.