Euphorbia rapulum Kar. & Kir.

Herbs, 10-30 cm tall, gray-brown suffused purplish. Rootstock a globose or radish-shaped tuber, 3-5 × 2-4 cm or even larger, sometimes branching. Stems single, 3-7 mm thick, many branched apically. Leaves alternate; stipules absent; basal scale-leaves amplexicaul, slightly light purple, especially abaxially, 1-2 cm × 3-6 mm; petiole short to almost absent; upper leaf blades obovate to elliptic, 3-4.5 × 0.6-2 cm, glabrous or ciliate on margins, base tapering and sometimes cordate, margin entire, apex obtuse; lateral veins few, from lower part of main vein. Inflorescence an indistinct terminal pseudumbel plus many subterminal cymes; primary involucral leaves 2-4, similar to and slightly smaller than normal leaves; cyathophylls 2, rarely 3, ovate-oblong, 0.8-1.3 cm × 3-6(-10) mm. Cyathium sessile; involucre broadly campanulate, ca. 2.5 × (2-)3-4.5 mm, exterior glabrous, interior hairy; lobes oblong, ± obtuse, margins densely ciliate; glands 4, pale brown, rounded or reniform. Male flowers many, exserted from involucre. Female flower: ovary pedicel ca. 3 mm and exserted from cup; ovary smooth, glabrous; styles free, persistent; style arms 2-lobed. Capsule ovoid-globose, 4.5-5.5 × 4-5 mm, longitudinally furrowed, smooth, glabrous. Seeds ovoid-terete, ca. 3 × 2 mm, yellow-brown to light gray, smooth, adaxially striate; caruncle sessile. Fl. and fr. Apr-Jun.

N Xinjiang [Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan].

Fields, plains, lower steppe slopes; 800-2000 m.

Euphorbia rapulum là một loài thực vật có hoa trong họ Đại kích. Loài này được Kar. & Kir. mô tả khoa học đầu tiên năm 1842.

小萝卜大戟（学名：Euphorbia rapulum）是大戟科大戟属的植物。分布于中亚以及中国大陆的新疆等地，生长于海拔800米至2,000米的地区，一般生长在港积平原、荒地和山前平原，目前已由人工引种栽培。