Origin and Habitat: Southern Namib, Namibia, north of the Orange River
Habitat and ecology: It grows in very arid areas.

• Piaranthus cornutus var. ruschii (Nel) Bruyns
• Piaranthus ruschii Nel

• Piaranthus cornutus N.E.Br.
• Piaranthus decorus var. cornutus (N.E.Br.) Meve
• Piaranthus cornutus var. grandis N.E.Br.
• Piaranthus nebrownii Dinter
• Piaranthus pulcher var. nebrownii (Dinter) A.C.White & B.Sloane
• Piaranthus pallidus C.A.Lückh.
• Piaranthus pulcher N.E.Br.

• Piaranthus cornutus var. mennellii (C.A.Lückh.) Plowes
• Piaranthus mennellii C.A.Lückh.

• Piaranthus cornutus var. ruschii (Nel) Bruyns
• Piaranthus ruschii Nel

Description: Piaranthus cornutusSN|18024]]SN|30433]] var. ruschii is a tiny, tufted, stapeliad from Namibia characterized by globose stems with small, but bright yellow, five-pointed flowers that can be surprisingly similar to forms of Piaranthus geminatusSN|30433]]SN|18024]] of the karoo. It flowers freely, usually in clumps. It distinguishes for the non erect staminal corona-lobes.
Stems: Reclining to upright, spherical or ovoidal, up to 2 cm long, hardly edged, with short-toothed tubercles.
Flowers: Appear singly or in twos near the tip of the shoot; corolla tips are ca. 1 cm long and are greenish yellow with dense white hairs. Flowers may have a pleasant, fruity smell, but more often a rancid butter smell.

Bibliography: Major references and further lectures
1) Werner Rauh “The Wonderful World of Succulents: Cultivation and Description of Selected Succulent Plants Other Than Cacti” Smithsonian Institution Press, 1984

Cultivation and Propagation: Piaranthus cornutusSN|30433]]SN|30433]] var. ruschii is an easy blooming plant when mature that require moderately watering through the growing season but enjoy plenty of water and some fertiliser in hot weather, this helps them to flower freely. Water more sparingly in winter according to temperatures. But, as with most asclepiads, it is unwise to leave them wet in cold weather. Winter care presents no problems at 5°C with plenty of light. Since roots are quite shallow, use a cactus mix or add extra perlite or pumice to regular soil potting soil. A gritty, very free-draining compost is suitable, and clay pots help the plants to dry out between watering.
Sun Exposure: Partial sun or light shade
Pest and diseases: Piaranthus species vary in their susceptibility to rotting, but are generally fairly easy to grow, especially if kept pest-free. They are very susceptible to stem and root mealy bugs, and damage from these may well initiate fungal attack. If you do have problems with a stem or with basal rotting, you can reliably isolate the healthy parts, dry them off, and re-root them in moist compost.
Cultural Practices: Re-pot every 2 years
Propagation: Easiest with stem cuttings. Allow cuttings to dry a day before planting. Stems must be laid (Not buried) on gritty compost and will then root from the underside of the stems. It can also be increased from seeds sowing in spring in moist, sandy peat moss.
Potting medium: Since roots are quite shallow, use a cactus mix or add extra perlite or pumice to regular soil potting soil. A gritty, very free-draining compost is suitable, and clay pots help the plants to dry out between watering.