大戟 da ji

Euphorbia barbellata Hurusawa; E. cavaleriei H. Léveillé & Vaniot; E. hurusawae Oudejans; E. hurusawae var. imaii (Hurusawa) Oudejans; E. imaii Hurusawa; E. jesonii Oudejans; E. kitagawae (Hurusawa) Kitagawa; E. labbei H. Léveillé; E. lanceolata T. N. Liou; E. lasiocaula Boissier; E. lasiocaula var. pseudolucorum Hurusawa; E. sinensis Jesson; E. sampsonii Hance; E. tchen-ngoi (Soják) Radcliffe-Smith; E. virgata Waldstein & Kitaibel var. kitagawae Hurusawa; Tithymalus tchen-ngoi Soják.

Herbs, perennial, 40-80(-90) cm tall. Rootstock vertical, cylindric, 20-30 cm × 6-14 mm thick, sometimes branched. Stems single or clustered, 3-6(-7) mm thick, upper parts 4- or 5-branched, pilose or glabrous. Leaves alternate; stipules absent; petiole absent or nearly so; leaf blade very variable, usually elliptic, occasionally lanceolate, narrowly oblong or oblanceolate, rarely linear, 3-7(-9.5) × 0.7-1.7(-2.4) cm, both surfaces glabrous or abaxially pilose or pubescent, base subrounded or subtruncate for lower leaves, attenuate for upper leaves, margin entire or serrulate, apex acuminate or acute; midrib raised abaxially, often grooved adaxially, lateral veins inconspicuous, much varied. Inflorescence usually a terminal compound pseudumbel, sometimes much branched, sometimes with slender long pedunculate cymes or pseudumbels from axils below; primary involucral leaves 4-7(-16), leaflike but shorter, narrowly elliptic, base rounded, apex acute, primary rays 4-7, 2-5 cm; cyathophylls 2, base ± truncate, apex subrounded with micro-tip. Cyathium sessile; involucre cuplike, ca. 3.5 × 3.5-4 mm, lobes rounded, irregularly ciliate; glands 4, pale brown, rounded or reniform-rounded, entire. Male flowers many, exserted from involucre. Female flower: ovary pedicel 3-5(-6) mm, exserted from cup; ovary densely tuberculate; styles free, persistent but easily fallen; style arms 2-lobed. Capsule globose, ca. 4.5 × 4-4.5 mm, sparsely tuberculate. Seeds long globose, ca. 2.5 × 1.5-2 mm, dark brown or slightly shiny, adaxially slightly colored striate; caruncle subpeltate, sessile. Fl. May-Aug.

Slopes, scrub, roadsides, fields, grasslands, steppes, sparse forests; common. Throughout China except Taiwan, Xinjiang, Xizang, Yunnan [Japan, Korea].

Euphorbia pekinensis is the most variable species in China, especially on indumentum, and requires much more extensive study.

The root is used medicinally.