大戟亚属 da ji ya shu

Trees, shrubs, or herbs. Stems always succulent, usually with prominent ribs or tubercles. Leaves opposite or alternate, each inserted on a callosed "spine shield" bearing 1 or 2 spines below a pair of pricklelike stipules; leaf blade often very small and scalelike, rarely persistent. Cyathia in small subterminal cymes; cyathophylls reduced, somewhat scalelike; cyathial glands without appendages, usually ± contiguous. Seeds usually without caruncle.

About 250 species: most numerous and diverse in the drylands of Africa but with a few species extending into the drier regions of Asia as far east as SE China; three species (two introduced) in China.

Some species are used as live fences. There are unconfirmed reports that Euphorbia sessiliflora Roxburgh extends into China. Though it has terete stems and lacks the characteristic spine shields, it has very similar axillary inflorescences and is possibly most closely related to this group.

Lower Taxa

• Euphorbia antiquorum Linnaeus
• Euphorbia neriifolia Linnaeus
• Euphorbia royleana Boissier