4. Pachypleurum xizangense H. T. Chang & R. H. Shan, Acta Phytotax. Sin. 18: 376. 1980.
西藏厚棱芹 xi zang hou leng qin
Plants 10–30 cm. Taproot elongate; caudex rather thick, 2–3 cm across, slightly woody. Stem well developed, caespitose, purplish, striate, branched. Basal leaves petiolate, wholly sheathing; sheaths inflated, purplish; blade oblong or oblong-ovate, 10–15 × 3–5 cm, ternate-2–3-pinnate, pinnae 3–4 pairs, remote; ultimate segments lanceolate or oblanceolate, 1–2 × 1–1.5 mm. Cauline leaves few, similar to basal, reduced, shortly petiolate or sessile. Umbels 3–6 cm across, enlarging after flowering up to 10 cm across; bracts 10–15, linear-lanceolate, ca. 15 mm, veins purplish, scabrous; rays 20–40, 3–5 cm, scabrous, slightly recurved in fruit; bracteoles 8–10, linear-lanceolate, 7–8 mm, scabrous; umbellules 15–20-flowered. Calyx teeth lanceolate, unequal, 1–1.5 mm. Petals white, oblong-ovate. Stylopodium conic; styles ca. 2 × stylopodium. Fruit broadly ovoid, 5–7 × 4–5 mm; vittae 1 in each furrow, 2 on commissure. Fl. Jun–Jul, fr. Aug–Sep.
Alpine meadows, grassy valley slopes; 3700–4600 m. Xizang.