Echidnopsis

Echidnopsis is a genus of succulent, cactus-like plants in the Apocynaceae, first described as a genus in 1871. They are native to eastern Africa and the Arabian Peninsula. 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.