Euphorbia tirucalli, Pencil Cactus
Euphorbia tirucalli, or Indian Tree Spurge, is a succulent, spineless shrub or tree with a heavy trunk, brown primary branches, and pencil-like, green, new branches. Leaves cluster at the tip of the branches, as do insignificant flowers within showy bracts. It is tropical to semi-tropical by nature and reliably winter hardy to USDA Zone 11. It is currently surviving in southern parts of Florida and California in Zone 10. It is drought tolerant and when grown outdoors in warm climates, the tree can reach heights of 30 feet and is typically used as a hedge or barrier. When grown in more temperate climates, it can be kept smaller and used as a houseplant.