Publication: Fl. Cap. (Harvey) 4: I. 1018 (1909)
Description
Piaranthus cornutus, the ‘Horned Piaranthus’ from the prominent corona lobes in the middle of the flower, is a clumping and prostrate species that spread over the ground forming large cushions of short-jointed brownish-green stems. The starfish-like flowers form in small bunches at the tips of the young stems, brownish-yellow, pale yellowish, or whitish on the inner face and heavily mottled with dark red.
Taxonomy: This is plant is often placed together with Piaranthus decorus (Piaranthus decorus subsp. cornutus), but the corona is quite different. Piarnthus decorus has outer corona lobes incumbent on the anthers with extremely large deeply furrowed crests, in Piaranthus cornutus the outer-corona lobes are erect and the crests are more delicate.
Stems: Procumbent or ascending, 1.5-5 (or under cultivation up to 8) cm long, 12-18 mm thick, globose, ovoid, oblong or cylindrical, very obtusely 4-angled, with 3–5 tubercle-like teeth along the angles, greyish- or glaucous-green often becoming brownish-green in full sun.
Flowers: 1- to several, but usually in pairs, above the middle or at the tips of the stems, erect, scentless or with sweetish odour of decaying fruits. Pedicels (4-)6-12(-18) mm long, 1-1.5 mm thick, glabrous. Sepals 2-4 mm long, lanceolate, acute, glabrous. Corolla 15-28 mm in diameter, very deeply lobed, without a distinct tube. Corolla lobes about c 10 mm long, 3-5 mm broad at the base, more or less free, lanceolate, acuminate, often some-what ascending (at an angle of ± 30°), tips often re-curved, glabrous on the back, velvety-puberulous on the inner face, brownish-yellow, pale yellowish, or whitish, with purple, crimson or brown dots, patches or tranverse bands (rarely with-out pattern), densely hairy. Hairs conical, white to purple-brown, 0.1-1 mm long. Corona 2.5-3(-3.5) x 3.5-4.7 mm. Outer corona-lobes about 1.2-2 mm long, 0.5-0.8 mm thick, narrowly linear-lanceolate or lanceolate-subulate, incumbent at the base upon the backs of the anthers and produced beyond them into connivent-erect acute tips, dorsally produced at the base into a subquadrate crest, 0.8-1.5 mm broad, truncate and tuberculate-denticulate at the top, yellow, without markings. Pollinia 0.45-0.6 x 0.28-0.35 mm.
Fruits (paired follicles): About 10 cm long.
Seeds: Mostly 5 x 3 mm.
Origin and Habitat
South Namibia, and north-western Republic of South Africa (Little Namaqualand)
Habitat and ecology: It grows in very arid areas often beneath large Aloe dichotoma trees.
Bibliography
Major references and further lectures
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N. E. Brown. “Flora Capensis”, Vol 4, page 518, 1909
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Focke Albers, Ulrich Meve “Illustrated Handbook of Succulent Plants: Asclepiadaceae: Asclepiadaceae” Volume 4 Springer Science & Business Media, 2002
From llifle page Piaranthus pulcher
Description
Piaranthus pulcher is a morphological or geographical form of the variable Piaranthus cornutus. It characterizes in the bright clear greenish-yellow flowers, marked all over with small rounded dark purple-brown spots. However the differences with standard P. cornutus are subtle if any. Piaranthus pulcher mentioned in old literature and sometimes offered in plant lists, should be fully synonymized with Piaranthus cornutus.
Stems: Tufted, 1-2.5 (or more) cm long, 8-12 mm thick, subglobose or oblong, obtusely 4-angled, with small tubercle-like teeth, glabrous, greyish-green or somewhat glaucous.
Flowers: 1–4 (often 2) together, near the middle or tips of the stems; pedicels erect, 6-12 mm long, stout, thickened upwards, glabrous. Sepals c. 4 mm long, linear-lanceolate, acuminate, glabrous. Corolla subrotate, without a distinct tube, c 2 cm in diameter, glabrous and dull greenish-brown on the back, inner face velvety-pubescent with white and purple hairs, bright clear greenish-yellow, marked all over with small rounded dark purple-brown spots. Corolla-lobes not spreading horizontally, 9-10 mm long, 4 mm broad at the base, thence tapering in a nearly straight line to the apex, with revolute margins. Corona-lobes 2 mm or rather more in length, linear-subulate, incumbent on the backs of and much exceeding the anthers, with short subdenticulate acute connivent-erect tips, dorsally produced at the base into a quadrate crest, flat and papillate on the top, clear deep yellow, without markings.
Origin and Habitat
North-western Republic of South Africa (Little Namaqualand).
Cultivation and Propagation
Piaranthus pulcher 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.
Source: Piaranthus pulcher, LLIFLE - Encyclopedia of living forms, CC-BY-SA, retrieved 2026-10-26.