Echidnopsis

Echidnopsis is a genus of succulent, cactus-like plants in the family Apocynaceae, first described as a genus in 1871.

[1] They are native to eastern Africa and the Arabian Peninsula.

[2][3] Echidnopsis quadrangula now Caralluma quadrangula Phylogenetic studies have shown the genus to be monophyletic, and most closely related to the genus Rhytidocaulon.

Marginally more distantly related is a sister branch comprising the genus Pseudolithos and the widespread Caralluma stapeliads of North Africa.

[5]