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" means "false-stone" and refers to their pebble-like appearance. It was originally proposed as Lithocaulon earlier in 1956, but this name was already in use for a genus of fossil algae. All species in this genus are highly succulent, small in size, and exhibit tessellation on their stems' surface. Their small flowers appear on the spherical body's surface.


 * Species


 * 1) Pseudolithos caput-viperae Lavranos - Somalia
 * 2) Pseudolithos cubiformis (P.R.O. Bally) P.R.O. Bally - N Somalia
 * 3) Pseudolithos dodsonianus (Lavranos) Bruyns & Meve - Somalia & Oman
 * 4) Pseudolithos gigas Dioli - Eastern Ethiopia
 * 5) Pseudolithos harardheranus Dioli - Somalia
 * 6) Pseudolithos horwoodii P.R.O. Bally & Lavranos - Somalia
 * 7) Pseudolithos mccoyi Lavranos - Yemen & Oman
 * 8) Pseudolithos migiurtinus (Chiov.) P.R.O. Bally - S + C Somalia
 * 9) Pseudolithos sphaericus (P.R.O. Bally) P.R.O. Bally - N Somalia

Taxonomy
Phylogenetic studies have shown the genus to be monophyletic, and most closely related to the widespread Caralluma stapeliads of North Africa. Marginally more distantly related is a sister branch comprising the genera Echidnopsis and Rhytidocaulon.