Description from Flora of China
Hymenidium linearilobum (W. W. Smith) Pimenov & Kljuykov.
Plants 30–60 cm. Root dark brown, conic, ca. 2.5 cm thick. Stem thinly ribbed, glabrous. Basal and lower petioles 8–12 cm, sheaths small, narrow; blades oblong-ovate, 6–13 × 4–8 cm, 3–4-pinnate; ultimate segments linear, 3–6 × 0.5–1 mm, acute. Leaves reduced upwards, petiole becoming entirely sheathing. Umbels 10–18 cm across; peduncle 8–15 cm; bracts 7–10, 3–4 cm, like upper leaves; rays 20–25, 5–9 cm, unequal, hispidulous; bracteoles 6–8, lanceolate to oblanceolate, 5–10 mm, green with narrow white margin, apex entire or pinnate; pedicels 10–20, 8–10 mm, hispidulous. Calyx teeth obsolete. Petals obovate, white. Anthers dark purple. Stylopodium short-conic. Fruit ovoid, 4–5 × 3.5–4.5 mm; ribs all broadly sinuate-winged; vittae 1 in each furrow, 2 on commissure. Fl. Jun–Jul, fr. Jul–Aug.
Mixed woodland margins, open low scrub, rocky slopes, screes; 2400–3000 m. W Sichuan, NW Yunnan.