Tridentea pachyrrhiza (Dinter) L.C.Leach

Small succulent forming dense clump of tightly packed stems 60-200 mm diam. Stems 30-60 mm long, 10-15 mm thick, greyish green; tubercles 2-3 mm long; leaf-rudiments 1-2 mm long. Inflorescence with flowers developing in rapid to gradual succession on peduncle 5-20 mm long (rarely up to 40 mm); pedicel 25-35 mm long, 3-5 mm thick, thickening towards apex, ascending, holding flower facing ± horizontally to upwards; sepals ±7 mm long, 3 mm broad at base, ovate, acuminate. Corolla 40-75 mm diam.; outside green, often spotted with purple or brown, with spots coalescing towards apices of lobes, with 7 slightly darker almost parallel slightly impressed nerves on each lobe; inside brown to purple-black irregularly mottled with yellowish, rugulose and papillate especially towards centre, papillae dome-shaped to ± cylindrical obtuse and fused into ridges, each with a darker apical spot (but no bristle); tube shallowly conical, with corolla thickened around mouth; lobes 20-25 mm long, 20-25 mm broad at base, spreading to reflexed, ovate-deltate, slightly convex, with crenulate abruptly erect and fleshy margins bearing subclavate vibratile cilia up to 3.5 mm long. Corona ±7 mm tall, 13-15 mm broad, yellow heavily marked with dark purple to red-purple marked with yellow (on inner lobes), raised on short stipe; outer lobes 4-5 mm long, 2.0-2.2 mm broad at base, ascending, trifid; central lobule ±4 mm long, narrowly deltoid, ± acute, slightly channelled down inner face; lateral lobules deltoid, widely diverging, 0.5-2.5 mm long; inner lobes 5-6 mm long, connivent becoming recurved above, terete above anthers, obtuse, near base with ascending laterally flattened dorsal horn 0.7-2.5 mm long and 0.5-1.0 mm broad near base.