Piaranthus cornutus 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-)20-28 mm diam., rotate, often with ascending lobes; inside white to yellow, with many fine red to red-brown dots or transverse bands, rarely uniformly white to yellow, covered with slender conical-acute papillae up to 1 mm long; tube ± absent; lobes 8-12 mm long, 3-5 mm broad at base, ascending with recurved tips to spreading, narrowly deltate, acuminate, with margins recurved, rarely with few vibratile clavate cilia up to 2 mm long near base. Corona 2.5-5.0 mm tall, 3.5-5.0 mm broad, yellow sometimes spotted with red-brown; outer lobes forming slightly to deeply rugulose-tuberculate crest to 0.8-1.5 mm broad behind inner lobes; inner lobes 1-2 mm long, 0.5-0.8 mm broad, adpressed to backs of anthers and exceeding them, usually steeply ascending towards centre, narrowly ovate-deltoid to linear, acute to denticulate.