Piaranthus geminatus (Masson) N.E.Br.

Stems 10-60(-150) mm long, 8-20(-25) mm thick, globose to subglobose, pale to dark grey-green, smooth to papillate; tubercles with apical deltoid leaf-rudiment 0.3-1.2 mm long, usually with 2 minute stipular denticles at base. Pedicel 2-20 mm long, 1-2 mm thick; sepals 2-4 mm long, 0.5-1.2 mm broad at base. Corolla (15-)20-42 mm diam., rotate; inside white, yellow, yellow-green or brown, transversely marked with red to brown, rarely uniformly yellow or red-brown, covered with fine slender conical-acute papillae <1 mm long; tube ± absent; lobes 8-18 mm long, 3-5(-6.5) mm broad at base, spreading, ovate to deltate, acute, with margins recurved, rarely with few clavate cilia up to 2 mm long near base. Corona 2.3-3.5 mm tall, 3.2-6.5 mm broad, yellow sometimes spotted with red; outer lobes forming narrow platform to ± absent below guide-rails, forming rounded to deeply rugulose-tuberculate crest to 1.0-2.2 mm broad behind inner lobes; inner lobes 1-2 mm long, 0.5-1.2 mm broad, adpressed to backs of anthers and usually exceeding them but not ascending beyond them, ovate-deltoid to linear, acute to denticulate.