Ligusticopsis macilenta (Franch.) J.M. Niu & J. Zhou, comb. nov. (Fig. 1).

Basionym: Peucedanum macilentum Franchet (1894: 142) . ≡ Kitagawia macilenta (Franch.) Pimenov (2017: 166) .

Type: — CHINA. Yunnan: Hokin, prope Koua-la-po, alt. 2800 m, 18 Aug 1886, Delavay 2476 (lectotype designated by Pimenov (2017: 166): P [P02272026!]; isolectotypes: K [K000685420!], NY [NY00406176!], P [P02272027!, P02272025!]) .

Description: —Perennial herbs. Plants 30–70 cm. Stems solitary or several, base clothed in fibros remnant sheaths, branched above, branches hollow, puberulous, nodes densely tomentose. Basal leaves numerous; petioles 5–10 cm, sheaths large, purplish, apex broadly auriculate, often pubescent and scarious-margined; blade triangular-ovate in outline, 3–4-pinnatisect, pinnae 5–6 pairs; ultimate segments linear, 1.5–3 × 0.8–1.2 mm. Compound umbels terminal; umbels 4–7 cm across; bracts 2–3, linear, entire or occasionally 3-lobed; rays 12–20(–30), 2–3 cm, slender, inner faces sparsely pubescent; bracteoles 6–8, linear, 3-lobed or pinnate, pubescent; umbellules 12–16-flowered. Calyx teeth conspicuous, lanceolate. Petals white, broad-obovate, ca. 1 mm, pubescent, stemens 5, stylopodium short-conic, styles short. Schizocarp ovoid-ellipsoid, ca. 3 × 2 mm; dorsal ribs prominent, lateral ribs narrowly winged; vittae 1–2 in each furrow, 4 on commissure.

Distribution and habitat: —Endemic to China, occurring in Sichuan Province. It grows in alpine grassland at elevations of 3000–4200 m.

Phenology: —Flowering and fruiting from August to September.

Vernacular name:—DZÑIJ· (Chinese name), xì liè ní gǎo běn (Chinese pronunciation).

Additional specimens examined: — CHINA. Sichuan: Muli County, Yazui forest farm, 28°12'6.83"N, 101°15'97.58"E, 3726 m, 12 August 2016, J. Zhou & Z. W. Liu 20160670 (Kunming Medical University) ; Kangwu temple, 28°20'14.33"N, 101°14'28.35"E, 3300 m, 12 August 2016, J. Zhou & Z. W. Liu 20160673 (Kunming Medical University) ; Mianya Township, 27°41'13.10"N, 101°13'26.55"E, 3215 m, 21 August 2020, J. Zhou, M. J. Guo & J. M. Niu Z20-063 (Kunming Medical University) ; Sanjia village, 28°12'3.41"N, 101°9'11.85"E, 3463 m, 24 August 2020, J. Zhou, M. J. Guo & J. M. Niu Z20-095 (Kunming Medical University) .

Notes: — Ligusticopsis macilenta was previously recorded from Heqing, Weixi and Tengchong of Yunnan Province based on flora records (Sheh 1992; Sheh et al. 2005). However, after re-examining the specimens identified as Peucedanum macilentum from Yunnan Province in the Chinese Virtual Herbarium (http://www.cvh.ac.cn/), it was found that these plants are misidentified, which in fact are Ligusticopsis glaucescens, L. brachylobum (Franchet 1894: 134) Leute (1969: 71) or Selinum cryptotaenium Boissieu (1903: 847) etc. Therefore, Ligusticopsis macilenta is currently distributed only in Sichuan Province based on available voucher materials.