Rhytidocaulon is a plant genus in the family

Apocynaceae Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of ...

, first described in 1962. It is native to northeastern

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and the Arabian Peninsula ;SpeciesThe Plant List, ''Rhytidocaulon''
/ref> # '' Rhytidocaulon paradoxum'' P.R.O.Bally - Ethiopia # '' Rhytidocaulon piliferum'' Lavranos - Somalia # '' Rhytidocaulon richardianum'' Lavranos - Somalia # '' Rhytidocaulon subscandens'' P.R.O.Bally - Somalia, Ethiopia # '' Rhytidocaulon tortum'' (N.E.Br.) 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 ''Pseudolithos'' is a genus of succulent flowering plants of the family Apocynaceae, indigenous to arid areas of Somalia, Yemen and Oman. Description and naming The plants were first described as a genus in 1965; the name ''"Pseudo-lithos"'' me ...

'' and the widespread ''

Caralluma ''Caralluma'' is a genus of flowering plants in the family Apocynaceae, consisting of about 120 species. In 1795 William Roxburgh published the name '' Stapelia adscendens'' for a plant found in India. He commented that the name for the plant ...

'' stapeliads of North Africa.P. Bruyns, C. Klak, P. Hanacek: ''Evolution of the stapeliads (Apocynaceae-Asclepiadoideae) - repeated major radiation across Africa in an Old World group. Molecular Phylogenetics and Evolution.'' 2014. v. 77, no. 1, p. 251--263. ISSN 1055-7903.

References

{{Taxonbar, from=Q3429900 Apocynaceae genera Asclepiadoideae