Scientific Name
Orbea wissmannii (O.Schwartz) Bruyns
Synonym(s)
Angolluma wissmannii, Caralluma wissmannii, Ceropegia wissmannii, Pachycymbium wissmannii
Scientific Classification
Family: Apocynaceae
Subfamily: Asclepiadoideae
Tribe: Ceropegieae
Subtribe: Stapeliinae
Genus: Orbea
Etymology
The generic name "Orbea" (pronounced "ORB-ee-uh") means "ringed; having a ring" and refers to the conspicuous ring-shaped structure, known as annulus, found in the flowers of this genus.
The specific epithet "wissmannii" (pronounced "wiss-MAHN-nee-eye") honors Hermann Wilhelm Leopold Ludwig Wissmann, after 1890 Hermann von Wissmann🡕 (1853–1905), a German explorer and colonial administrator in Africa.
Subspecies and Varieties of Orbea wissmannii
- Orbea wissmannii var. eremastrum
- Orbea wissmannii var. wissmannii
Origin of Orbea wissmannii
Orbea wissmannii is native to Saudi Arabia, Oman, and Yemen.
Description of Orbea wissmannii
Orbea wissmanii is a low-growing succulent with erect to ascending, 4-angled, gray-green stems often mottled with brown or purple. The fleshy stems can grow up to 3 inches (7.5 cm) long, forming cushion-like masses up to 3.3 feet (1 m) across. The angles of the stems are lined with prominent conical tubercles.
The flowers are deeply and narrowly lobed and appear in late summer or fall, reaching a diameter of 10 inches (25 cm). They are very variable in color, mostly brownish-red at the base and golden-yellow to bright-yellow towards the apex.
How to Grow and Care for Orbea wissmannii
Hardiness: USDA hardiness zone 9b to 11b: from 25°F (-3.9°C) to 50°F (10°C).
Several species are fairly easy to grow. Others, often those with slightly hairy stems and the more unusual flowers, are more challenging and require careful watering (with some fertilizer) during the growing season and complete withdrawal of water during the winter months. A minimum winter temperature of 10°C (50°F) is acceptable, provided that plants are kept dry. A heated growing bench or incubator may help delicate plants to get through the colder months. However, many species live under shrubs in their habitat and prefer light shade rather than full sun.
A gritty compost is essential, and clay pots are advisable for the more delicate species. Some growers prefer mineral-only compost to minimize the risk of fungal attack on roots. A layer of grit on the compost surface prevents moisture from accumulating around the base of the stems.
Keeping Stapelias and their roots free of pests such as mealybugs is the real key to success, as fungal attacks often result from insect damage to stems.
See more at How to Grow and Care for Stapelia.
Links
- Back to genus Orbea
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
Photo Gallery
Click on a photo to see a larger version.
