青藏大戟 qing zang da ji

Euphorbia przewalskii Prokhanov.

Herbs, perennial, 15-30 cm tall. Rootstock a short, deeply buried rhizome, 8-20 cm × 3-6 mm thick. Stems single or in small groups, to 5 mm thick, vegetative portion often short and inconspicuous, often drying a rather bright green, smooth and glabrous. Leaves alternate, increasing in size up stem; stipules absent; basal scale-leaves soon lost; petiole ill-defined, to 2 mm, relatively broad; leaf blade ovate to oblong, to 1.8-3 × 1-1.5 cm, mostly much smaller, base subtruncate to shallowly cordate, margin repand-denticulate, often undulate, apex rounded; midrib and lateral veins inconspicuous. Inflorescence a terminal pseudumbel, sometimes compound; primary involucral leaves 3-5, ovate-triangular, amplexicaul, 1-3 × 1.2-3 cm, margin denticulate, base amplexicaul, primary rays 3-5, 1-5 cm; cymes at first forked but then often reverting to small-leaved vegetative shoots; cyathophylls 2, similar to primary involucral leaves, but smaller. Cyathium stipe to 4 mm; involucre broadly campanulate, 2.5-3.5 × 4-6 mm, glabrous, lobes oblong, apex 2-lobed or slightly repand, inconspicuous, glabrous or sparsely ciliate; glands 5, dark brown, transversely reniform or oblong-elliptic, entire. Male flowers many, exserted from involucre. Female flower: ovary pedicel 3-5 mm, exserted from cup, strongly reflexed at anthesis; ovary smooth, glabrous; styles very short, free, strongly recurved, persistent; style arms unlobed or emarginate. Fruiting pedicel 3-10 mm; capsule ovoid-globose, 4-5 × 4-5 mm, very faintly rugulose, glabrous. Seeds ovoid-globose, 2.5-3 × 1.8-2.3 mm, pale fawn with brown marbling, smooth, matte, with dark adaxial line; caruncle subglobose, peltate, yellowish, very shortly stipitate. Fl. and fr. May-Aug.

● Grasslands along slopes of lakesides; 2800-3900 m. Gansu (Gaotai, Jiuquan), Ningxia (Yanchi), Qinghai, Xizang.