52. Euphorbia pachyrrhiza Karelin & Kirilov in Bull. Soc. Imp. Naturalistes Moscou. 14: 745. 1841.
长根大戟 chang gen da ji
Herbs, perennial, 20-60 cm tall. Root thick and long, 30-50 × ca. 1 cm in diam., apex many branched, with remains of old stems. Stem ca. 3 mm thick, reddish purple, often with sterile branches from lower axils. Leaves alternate; stipules absent; petiole absent or nearly so; leaf blade elliptic or oblong-obovate, 1-2.2 × 0.4-0.7(-1.1) cm, glabrous, base subcuneate, usually finely serrate, very variable, apex rounded; lateral veins inconspicuous. Inflorescence a terminal pseudumbel, usually also with axillary cymes from subterminal axils; primary involucral leaves 3 or 4(or 5), similar to normal leaves, primary rays 3 or 4, 1-3 cm; cymes simple or once-forked; cyathophylls 2, obovate-elliptic, base attenuate, margin finely serrulate, apex rounded. Cyathium usually reddish purple, stipe 3-7 mm; involucre broadly cuplike, ca. 4.5 × 3-4 mm, exterior glabrous, interior densely tomentose opposite glands, lobes rounded, white tomentose inside; glands 4, brown, reniform-rounded. Male flowers many, exserted from involucre. Female flower: ovary exserted from cup, densely tuberculate; styles free, easily fallen; style arms slightly 2-lobed. Fruiting peduncle 3-5 mm; capsule cylindric-globose, [3.5-]5 × [3-]5 mm, hardly furrowed, exserted from involucre, densely tuberculate, reddish brown. Seeds compressed ellipsoid, ca. 3 × 2 mm, dark or light brown; caruncle white, sessile. Fl. and fr. Jun-Aug.
Dry stony slopes, steppes; 1200-2700 m. Xinjiang (Ili He valley, Tacheng) [Kazakhstan, Kyrgyzstan, Tajikistan].