Origin and Habitat
Euphorbia obesa is a rare endemic of the Great Karoo, south of Graaff-Reinet in the Eastern Cape.
Euphorbia obesa is a small succulent with a ball-shaped, usually solitary stem that becomes cylindrical with age. The stem is grey-green and marked with horizontal red-brown or purple bands. It grows up to 30 cm tall, up to 10 cm in diameter, and almost always has eight slightly raised ribs. The tiny leaves fall off very soon after appearing. Male and female flowers are born on different plants. They are yellow and appear in summer on branched stalks at the top of the stem. Fruits are small 3-angled capsules.
It likes a sunny position, but it can also be grown outdoors where the frost is not too severe. It can tolerate temperatures down to -5°C (-10° if the roots are kept dry). It does best in a mineral soil, but is tolerant of a wide range of soil types. Good drainage is essential. Water sparingly during the summer months and keep dry in winter. It is a slow-growing, long-lived plant, and once established, it will be content in its position and with its soil for years. It can tolerate moderate shade, and a plant that has been growing in shade should be slowly hardened off before placing it in full sun, as the plant will be severely scorched if moved too suddenly from shade into sun.