Description from Flora of China
Herbs (annual, biennial, or perennial), shrubs, or trees, very rarely subscandent, sometimes rhizomatous, monoecious or, rarely in Flora area, dioecious; indumentum of simple hairs, often absent, all parts with abundant white, very rarely yellow, latex; roots fibrous or tuberous. Stems sometimes succulent, terete or variously winged or tuberculate. Leaves alternate or opposite, rarely verticillate; stipules present or not, sometimes modified into glands or prickles; petiole often ill-defined to absent; leaf blade usually entire, sometimes serrulate or dentate. Inflorescence a flowerlike cyathium, single or often several in terminal or axillary, dichasial or monochasial cymes often in a "pseudumbel" with a terminal ± sessile cyathium subtended by a whorl of pedunculate cymes, each subtended by an involucral leaf; cyathium consisting of a bowl-shaped to tubular involucre subtended by a pair of bracts, "cyathophylls," enclosing several clusters of male flowers and 1 central female flower, occasionally cyathia unisexual, involucre margin with 4 or 5 lobes, cyathial glands (1-)4 or 5(-7), mostly alternating with involucral lobes, sometimes with petaloid appendages or a pair of horns. Male flower reduced to a single stamen, with an articulation at junction of pedicel and filament, subtended by slender bracteoles. Female flower pedicellate, reduced to a single ovary, rarely subtended by a very reduced perianth; ovary 3-loculed; ovules 1 per locule; styles 3, free, sometimes partly connate; stigma 2-lobed or not, ± capitate. Fruit a capsule, breaking into 3 2-valved cocci, dehiscence usually explosive, very rarely almost indehiscent. Seeds 1 per locule, globose to ovoid or ± cylindric; caruncle present or not; endosperm abundant; cotyledons large.
Many species are grown as ornamentals, particularly the more succulent species by specialist collectors. Members of Euphorbia subg. Esula are grown as garden plants, while E. pulcherrima and E. milii are extremely important in the horticultural trade. Some species have been investigated as sources of rubber but without great success; others are of possible interest for the seed oils. Many, perhaps most, species have been used to some extent medicinally.
Euphorbia consanguinea Schrenk has been recorded as being used in Chinese traditional medicine in Xinjiang, and E. schugnanica B. Fedtschenko and E. seguieriana Necker have been reported from Xinjiang from local taxonomic work, but no material has been seen and these records must remain doubtful. Further taxa have been recorded for China by Govaerts et al. (World Checkl. Euphorbiaceae: http://www.kew.org/wcsp/home.do), but these could not be confirmed. These include Himalayan species E. jacquemontii Boissier and E. pseudosikkimensis (Hurusawa & Yu. Tanaka) Radcliffe-Smith, which might occur in Xizang; the C Asian species E. andrachnoides Schrenk, E. microcarpa (Prokhanov) Krylov, and E. potaninii Prokhanov, from W Siberia, Mongolia, and Kazakhstan, which could extend into the adjacent area of N and NW China; and widespread Eurasian taxa E. falcata Linnaeus and E. palustris Linnaeus, which might also extend into NW China.
Up to 2000 species: worldwide, particularly in drier areas of the tropics, especially diverse in Africa; one major group centered in temperate regions; 77 species (11 endemic, nine introduced) in China.
(Authors: Ma Jinshuang (马金双); Michael G. Gilbert)