甘肃大戟 gan su da ji

Euphorbia yinshanica S. Q. Zhou.

Herbs, erect, to 20 cm tall, gray-green. Rootstock tuberous or rhizomatous, 10-30 × 3-7(-20) mm, branched or not. Stems often solitary, 5-7 mm thick, upper parts with many slender axillary branches, thinly pilose. Leaves mostly alternate, occasionally opposite on lateral branches; stipules absent; basal scale-leaves few, relatively long and narrow; petiole absent; leaf blade very variable, linear, linear-lanceolate, or oblanceolate, usually oblong, 6-9 × 1-2 cm, gray-green, sparsely pilose, base cuneate, margin entire, apex rounded or acuminate; midrib prominent abaxially, lateral veins inconspicuous. Inflorescence an inconspicuous terminal pseudumbel surrounded by many axillary cymes; primary involucral leaves 3-5(-8), similar to normal leaves, primary rays usually 5, 1-3 cm; cymes rather congested; cyathophylls 2, ovate-triangular, 2-2.5 × 2.2-2.7 cm, base truncate or emarginate, apex acute. Cyathium sessile; involucre campanulate, 2.5-3 × 2.5-3 mm, lobes triangular-ovate, entire; glands 4, dark brown to brownish yellow, rounded. Male flowers many, exserted from involucre. Female flower: ovary pedicel ca. 3 mm and exserted from cup; ovary smooth, glabrous; styles connate below middle, persistent; style arms shortly 2-lobed. Capsule trigonous-globose, 5-5.8 × 5-6 mm, obscurely rugose, glabrous. Seeds trigonal-ovoid, ca. 4 × 4 mm, light brown to gray-brown, smooth, adaxially striate; caruncle white, stipitate. Fl. and fr. Apr-Jun.

● Steppes, slopes, valleys, scrub, fields, forest margins. Gansu, Hebei (Gaocheng, Neiqiu), Henan, Hubei (Suixian), N Jiangsu, Nei Mongol (Yin Shan), Ningxia, Qinghai, Shaanxi, Shanxi, NW Sichuan.

This species is similar in general to Euphorbia fischeriana but differs by the glabrous, not pilose, ovary.

The root is used medicinally.