Pseudolithos

Pseudolithos is a genus of succulent flowering plants of the family Apocynaceae, indigenous to arid areas of Somalia, Yemen and Oman.

Pseudolithos
Pseudolithos migiurtinus plant in cultivation
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Gentianales
Family:	Apocynaceae
Subfamily:	Asclepiadoideae
Tribe:	Ceropegieae
Genus:	Pseudolithos P.R.O.Bally

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.^[1] 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.^[2][3]

Species ^[4]

picture	species	distribution
	Pseudolithos caput-viperae Lavranos	Somalia
	Pseudolithos cubiformis (P.R.O. Bally) P.R.O. Bally	N Somalia
	Pseudolithos dodsonianus (Lavranos) Bruyns & Meve	Somalia & Oman
	Pseudolithos gigas Dioli	E Ethiopia
	Pseudolithos harardheranus Dioli	Somalia
	Pseudolithos horwoodii P.R.O. Bally & Lavranos	Somalia
	Pseudolithos mccoyi Lavranos	Yemen & Oman
	Pseudolithos migiurtinus (Chiov.) P.R.O. Bally	S + C Somalia
	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.^[5]