Euphorbia thomsoniana Boiss.

Herbs, 20-30 cm tall. Root terete, few branches, 30-50 cm × 6-10 mm. Stems many branched basally, slightly purplish, glabrous. Leaves alternate; stipules absent; basal scale-leaves purple or light red, ca. 5 × 3 mm, overlapping; leaf blade elliptic, 2-3 × 1-1.6 cm, glabrous, base subrounded, apex rounded; lateral veins inconspicuous. Primary involucral leaves 5-8, broadly ovate, ca. 2.5 × 1-2 cm, base subrounded, apex slightly narrow, primary rays 5-8, 1-4 cm; cyathophylls 2, triangular-ovate, ca. 1.5 × 1.4 cm, base subtruncate, apex acuminate. Cyathium sessile; involucre campanulate, 4-5 × 4-5 mm, lobes triangular, slightly bent inside, densely white pubescent inside and on margin, sparsely white pilose outside; glands 4, dark brown, reniform, shortly stalked, suberect, sparsely shortly pilose. Male flowers many, little exserted from involucre. Female flower: ovary usually not exserted from cup, sparsely shortly pilose; styles connate below middle, persistent; style arms 2-lobed. Capsule subglobose, 6-7 × ca. 7 mm, sparsely shortly pilose. Seeds ovoid-globose, ca. 6.5 × 5 mm, light gray with brown reticulum, smooth; caruncle present. Fl. and fr. Jun-Sep.

Xinjiang (Tian Shan) [Afghanistan, NW India, Kashmir, Kazakhstan, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan].

Subalpine meadows, scrub, stone hills; 2000-4500 m.

Euphorbia tianshanica (Prokhanov) Popov; Tithymalus tianshanicus Prokhanov.

Euphorbia thomsoniana là một loài thực vật có hoa trong họ Đại kích. Loài này được Boiss. mô tả khoa học đầu tiên năm 1862.

天山大戟（学名：Euphorbia thomsoniana）为大戟科大戟属的植物。分布于巴基斯坦、中亚、印度以及中国大陆的新疆等地，生长于海拔2,000米至4,500米的地区，多生在灌丛、干旱沙质、高山草甸、石质山坡以及岩石缝中，目前已由人工引种栽培。