Subdivision of Rhytidocaulon macrolobum(Asclepiadaceae)

Abstract

Within Rhytidocaulon macrolobum Lavranos, which is a widespread stapeliad in Saudi Arabia and in the Yemen, the subspecies minimum Meve & Collenette is described as new. This taxon is restricted to SW Saudia Arabia; it can be easily recognized by its miniature flowers, which are conspicuously smaller than the diameter of the stems, and by its bright-coloured corona.