Subspecies, varieties, forms and cultivars of plants belonging to the Orbea wissmannii group

• Caralluma meintjesiana Lavranos: (= Orbea wissmannii) Flowers are fleshy stars with 5 narrow, linear lobes, mostly light green with a blood red centre but very variable. Distribution: Saudi Arabia, Yemen, Oman.
• Orbea wissmannii (O.Schwartz) Bruyns: Corolla lobes 12-20 mm long and more than 3 mm wide, strongly curved to touch each other behind lobe and lobes convex adaxially; yellow more or less suffused with red or red becoming paler toward apex, glabrous or covered with short papillae; corona 3-4 mm tall x 3-4 mm in diameter.
• Orbea wissmannii var. eremastrum (O.Schwartz) Bruyns: Corolla lobes 12-20 mm long and more than 3 mm wide, slightly folded back and lobes lightly convex adaxially; yellow suffused with red (sometime flesh-coloured) in proximal half, greenish yellow to yellow towards tip, glabrous or covered with short papillae; corona 3-4 mm tall x 3-4 mm in diameter.
• Orbea wissmannii var. parviloba Bruyns: Corolla lobes 9-10 mm long and less than 2 mm wide, pale yellow, covered with white hairs. Corona 1.5-2 mm tall,2.5 mm in diameter. Distribution: Yemen.