Origin and Habitat: Republic of South Africa (Northern Cape, Western Cape)
Altitude range: Western Mountain Karoo to 1300 metres above sea level.

• Piaranthus geminatus subs. decorus (Masson) Bruyns
• Caralluma decora (Masson) Schltr.
• Obesia decora (Masson) Haw.
• Orbea decora (Masson) Steud.
• Piaranthus decorus (Masson) N.E.Br.
• Stapelia decora Masson
• Stisseria decora (Masson) Kuntze

• Piaranthus geminatus (Masson) N.E.Br.
• Caralluma geminata (Masson) Schltr.
• Obesia geminata (Masson) Haw.
• Podanthes geminata (Masson) G.Nicholson
• Stapelia geminata Masson
• Stisseria geminata (Masson) Kuntze
• Piaranthus barrydalensis Meve
• Piaranthus disparilis N.E.Br.
• Piaranthus disparilis var. immaculatus C.A.Lückh.
• Piaranthus globosus A.C.White & B.Sloane
• Piaranthus pillansii N.E.Br.
• Piaranthus pillansii var. fuscatus N.E.Br.
• Piaranthus pillansii var. incostans N.E.Br.

• Piaranthus geminatus subs. decorus (Masson) Bruyns
• Caralluma decora (Masson) Schltr.
• Obesia decora (Masson) Haw.
• Orbea decora (Masson) Steud.
• Piaranthus decorus (Masson) N.E.Br.
• Stapelia decora Masson
• Stisseria decora (Masson) Kuntze
• Piaranthus serrulatus (Jacq.) N.E.Br.
• Caruncularia serrulata (Jacq.) Don
• Obesia serrulata (Jacq.) Sweet
• Stapelia serrulata Jacq.
• Stisseria serrulata (Jacq.) Kuntze

• Piaranthus geminatus var. foetidus (N.E.Br.) Meve
• Piaranthus foetidus N.E.Br.
• Piaranthus foetidus var. diversus N.E.Br.
• Piaranthus foetidus var. multipunctatus N.E.Br.
• Piaranthus foetidus var. pallidus N.E.Br.
• Piaranthus foetidus var. purpureus N.E.Br.

Description: Piaranthus decorusSN|18048]]SN|18048]] is a clumping and prostrate species that spread over the ground forming large cushions of jointed brownish-green stems. The starfish-like flowers form in small bunches at the tips of the young stems, cream-yellow or green-yellow with bright to dark red-brown or brown dots, patches or transverse bands and densely velvety-hairy.
Stems: Decumbent, 1.5-5 cm long, or under cultivation sometimes very much longer, 12-20 mm thick, obscurely or very obtusely 4-angled, oblong, with 3–5 small tubercle-like teeth along each angle, glabrous, greyish-green, or under cultivation green, slightly glaucous.
Flowers: In pairs above the middle of the stems, erect with sweetish odour of decaying fruits. Pedicels 5-20 mm long. Sepals about 3 mm long, 1-1.5 mm wide, ovate-lanceolate, acute or acuminate, glabrous;. Corolla 1.5-3 cm in diameter, rotate, without a distinct tube, lobed to 3/4 of the way down. Corolla-lobes 10-12 mm long, 4-5 mm broad at the base, usually horizontally expanded, lanceolate, acute, apically often recurved, glabrous on the back, cream-yellow or green-yellow with bright to dark red-brown or brown dots, patches or transverse bands on the inner face, densely velvety-hairy not ciliate, hairs 0.1 - 0.5 mm, conical, white to bright purple ivory-coloured. Corona about 2.5 - 3 (-3.5) x 4.2 - 5 mm. Inner corona-lobes about 1.2-2 mm long, 0.5 - 1 mm thick, closely incumbent upon the backs of the anthers and shorter than or slightly exceeding them, lanceolate or ovate, varying (even in the same flower) from acute to irregularly toothed at the apex, dorsally produced at the base into a short transversely rectangular crest, truncate or irregularly toothed at the rather acute-edged dorsal margin, with slight ridges from the edge to the inflexed part of the lobe, yellow, not spotted. Pollinia 0.5 - 0.6 x 0.3 – 0.35 mm.
Fruit (follicles): The fruit are paired spindle-shaped capsules about 8 cm long and 0.5 cm across, resembling the horns of an antelope, with the tightly packed seeds inside. At maturity they split open to release numerous small brown seeds crowned with long white hairs.
Seeds: About 4.5 x 2.5 mm.
Note: In this species most of the corona-lobes are entire at the apex, but some of them are toothed, as represented in Jacquin's figure of Stapelia serrulataSN|18055]]SN|18055]], but that plant and Piarantus decorus, Masson, are one species (N. E. Brown 1909).

Bibliography: Major references and further lectures
1) N. E. Brown. “Flora Capensis”, Vol 4, 1909
2) 2) Focke Albers, Ulrich Meve “Illustrated Handbook of Succulent Plants: Asclepiadaceae: Asclepiadaceae” Volume 4 Springer Science & Business Media, 2002
3) James Cullen, Sabina G. Knees, H. Suzanne Cubey “The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass” Cambridge University Press, 11/August/2011
4) Foden, W. & Potter, L. 2005. Piaranthus geminatus (Masson) N.E.Br. subsp. decorus (Masson) Bruyns. National Assessment: Red List of South African Plants version 2014.1. Accessed on 2015/02/15