Euphorbia clava
Originally East Cape, It is an easy species to grow that is suited for any well drained soil in full sun. But young plant are happy growing indoors, where they can easily reach the ceiling. Give the plant an airy growing medium which mainly consists of non organic. Water regularly during the active growing season from March to September. No water should ever be allowed to stand around the roots. Keep almost completely dry in winter. It is a moderately fast grower, and will quickly become large landscape masterpieces in just 3-5 years. If plant becomes very red, this is a sign that the roots have not developed properly. It is a relatively fast growing and 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. Like quite small pots, repott in very later winter, early spring. Can be pruned for shape and branching. Frost tender, frost free zones only.
Propagation: It is easy to propagate by cuttings in late spring to summer, just take a cutting of the plant let it dry for 1 or 2 weeks and stuff it in the ground (preferably dry, loose, extremely well draining soil).

Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz

Bloom Season	Late winter to spring
Botanical Name	Euphorbia clava
Dormancy	Winter
Family	Euphorbiaceae
Flower Color	Bright yellow
Growth Habit	Cylindrical
Hardiness Zone	9b11
Mature Size	624 in.
Native Area	South africa
Resistance	25° f