Description from Flora of China
Carum vaginatum (H. Wolff) M. Hiroe.
Plants 10–25 cm. Rootstock short, thick, ca. 4.5 × 0.8 cm. Stems 1–2, 1–2-branched or unbranched. Basal petioles 5–18 cm, sheath ovate; blade triangular, 5–13 × 5–8 cm, ternate-2–3-pinnate; pinnae 4–6 pairs; ultimate segments elongate-linear, 10–30 × 0.5–2 mm. Cauline leaves 1–2-pinnate, reduced upwards. Umbels 3–4 cm across, often subtended by uppermost leaf with broad sheath; bracts absent or occasionally 1; rays 8–15, 1–2 cm, unequal; bracteoles absent; umbellules 8–12 mm, 10–20-flowered; pedicels 1–5 mm. Calyx teeth minute triangular, ca. 0.2 mm. Petals white, entire, apex acute, radiant. Young fruit oblong-ovoid (mature fruit unknown); vittae 1 in each furrow, 2 on commissure. Fl. and fr. Jul–Sep.
See the taxonomic comment under Sinocarum cruciatum.
Forest margins, brushy alpine meadows; 3200–4300 m. W Sichuan, SE Xizang, NW Yunnan.