Scientific Name
Rhytidocaulon macrolobum Lavranos
Scientific Classification
Family: Apocynaceae
Subfamily: Asclepiadoideae
Genus: Rhytidocaulon
Description
Rhytidocaulon macrolobum is a small succulent with light to dark brown branched stems that become grayish-brown as they age. They are cylindrical with a rough, wrinkled, aged texture. The main stem is up to 12 inches (30 cm) long and up to 0.8 inches (2 cm) in diameter. Branches are shorter and more slender. Leaves are small and lanceolate to narrowly triangular. Flowers are up to 0.6 inches (1.5 cm) across, variable in color and banding. They are usually black or dark-maroon, but also dark-purple, dark green-brown or green inside, basally cream-colored cross-banded with red-brown, and with purple frilly vibratile hairs on the margins. The center of the flowers is often with red tones.

Hardiness
USDA hardiness zone 9a to 11b: from 25 °F (−3.9 °C) to 50 °F (+10 °C).
How to Grow and Care
Stapeliads are relatively easy to grow. However, they should be treated as outdoor plants as they will easily rot indoors and cannot flower without exposure to outdoor temperature fluctuations. They should be grown under cover so that watering can be controlled. They require a reasonable amount of sunlight to promote flowering and maintain a well-shaped plant. Very shady positions will produce very poor flowering. Stapeliads come from climates where they survive extremely high temperatures in the summer months, so most growth is in spring and autumn, with flowering in autumn when the weather starts to cool down. Water in moderation when needed in the growing season, making sure soil is fairly dried out between waterings. Do not water between November 1 and March 1.
The easiest and best way to propagate Stapeliads is from stem cuttings, which can be taken virtually throughout the year. Using the seed is also a method of propagation.
See more at How to Grow and Care for Stapeliads.
Origin
Native to Saudi Arabia, Yemen, and Somalia.
Links
- Back to genus Rhytidocaulon
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus