Description from Flora of China
Carum leptocladum Aitchison & Hemsley, Trans. Linn. Soc. London, Bot. 2: 66. 1888-1889.
Plants 10–40 cm, sparsely pubescent throughout, sometimes glabrescent. Lower leaves petiolate, petiole 1–2 cm; blade lanceolate, oblong-lanceolate or obcuneate in outline, 2–5 × 0.5–2 cm, 3-lobed, 3-toothed, or entire; ultimate segments almost linear, 0.6–40 × 0.6–2.8 mm, base tapering into the long petiole, apex acute. Leaves reduced upwards, ultimate segments becoming narrower. Umbels numerous, usually opposite leaves, 2.5–6 cm across, open; peduncles long, 1.8–5 cm; bracts 2–5, lanceolate-acute, 2–3.5 mm, white membranous, central stripe yellow, abaxially puberulous, margins ciliate; rays 5–10, 1.5–5 cm, very slender, divergent; bracteoles 5–6, ovate-lanceolate, 1–2.5 mm, much shorter than flowers, similar to bracts; umbellules ca. 10-flowered, 6–10 mm across, pedicels 2.5–12 mm, longer in fruit. Petals ca. 1 × 0.5 mm. Fruit ovoid, 2–3 × 1.2–1.8 mm; bristles 0.2–0.4 mm. Fl. Apr–May, fr. Jun.
Grasslands, stable sandy places, cultivated land; ca. 1500 m. W Xinjiang [Afghanistan, Tajikistan, Turkmenistan, Uzbekistan].