亮蛇床 liang she chuang

Pleurospermum glaucescens H. Wolff.

Plants 0.4–2 m, stout. Taproot 2–3 cm thick, branched. Stem erect, striate, branched above. Basal petioles 10–20 cm; sheaths somewhat inflated, 2–7 cm broad, purplish; blade triangular-ovate, 8–10 × ca. 8 cm, ternate-2–3-pinnate, glabrous or scabrid; pinnae 4–8 pairs; ultimate segments oblong-ovate or lanceolate, 10–20 × 5–8 mm. Umbels 8–10 cm across (to 20 cm across in fruit); bracts 12–15, linear, densely hispid, recurved, caducous; rays 12–28(–50), subequal, 5–7 cm, elongating in fruit, hispid; bracteoles 5–10, linear, entire or apex 2–4-lobed, ca. equaling pedicels, recurved. Calyx teeth linear-lanceolate, ca. 1 mm. Petals white or faintly pinkish, pinkish in bud. Styles short when young, ca. 2 × stylopodium in fruit. Fruit ovoid, ca. 4 × 3.5–4 mm; dorsal ribs subequal, narrowly winged, lateral ribs broad-winged; vittae 1 in dorsal furrows, 2–3 in lateral furrows, 4–6 on commissure. Fl. Jul–Aug, fr. Sep–Oct.

Montane forests; 2500–4100 m. SW Sichuan, C and NW Yunnan.

The type of Pleurospermum glaucescens (Yunnan: Lijiang, J. F. Rock 4481, E) and Wolff’s original description show no membranous margin on the bracteoles, well-developed, linear calyx teeth, and dorsally compressed fruit. These features are uncharacteristic of Pleurospermum, and so this species is treated here as a synonym of Selinum cryptotaenium.