Euphorbia fanjingshanensis N. Wei, Lei Shi & Q. F. Wang sp. nov.

Type.

China • Guizhou: Tongren City, Fanjingshan Mountain, near the summit, 27.9143, 108.6922, 2263 m, 25 July 2024, N. Wei & Z. H. Xin WN 16 (holotype: HIB!; isotypes: HIB!, PE!)

Diagnosis.

Euphorbia fanjingshanensis is most similar to E. micractina and E. hylonoma, but differs from E. micractina and E. hylonoma mainly by its lanceolate leaves with pointed tips, crimson to reddish peduncles and raylet-leaves, moderately tuberculate capsules, and dark brown ovoid-globose seeds (Table 2).

Description.

Herbs, erect, up to 75 cm tall. Root thick, up to more than 10 cm × 3–5 mm. Stems 3–7 mm thick, in clusters of up to 8, upper parts usually unbranched, pilose or glabrous. Leaves lanceolate, 4–10 × 1–2 cm, both surfaces glabrous; adaxial surface green, abaxial sometimes light purple; base attenuate, apex acute, margin entire; midrib prominent abaxially, often grooved adaxially; lateral veins 6–10 pairs, inconspicuous. Synflorescences arranged in a terminal pseudumbel, usually also with long-pedunculate dichasial cymes from axils; cymes 2–4 - forked; primary involucral leaves 5, similar to normal leaves, margin entire, base rounded, apex rounded, primary rays 2.0– 5.5 cm long; raylet-leaves and subcyathial raylet-leaves 2 or 3, triangular-ovate, 0.7–1.7 × 0.5–1.5 cm, green with reddish margin to red, sessile. Cyathia sessile; involucre campanulate, ca. 2.5 × 2.5–3.5 mm, lobes pink to red, triangular to linear-triangular, glabrous; glands 4, occasionally 5, pale yellow to dark brown, reniform. Male flowers numerous, exserted from the involucre, 1.0– 1.5 mm. Pollen grains are radially symmetrical and 3 - colporate, ca. 30 × 25 μm, nearly oblate in equatorial view with a longer equatorial axis and a shorter polar axis, trilobed-circular in polar view, and ornamented with separate perforations ranging from circular and broadly elliptic to linear-oblong; Female flower with ovary globose, tuberculate; styles connate for less than half their length, red to crimson, sometimes green with flushed red apex, persistent but easily fallen; style arms bifid. Capsule globose, ca. 4.5 × 4.0– 4.5 mm, moderately tuberculate with short tubercles ca. 1 mm long. Seeds ovoid-globose, ca. 2.5 × 2 mm, dark brown, slightly shiny, smooth, adaxially striate; caruncle peltate, shortly stipitate.

Distribution and ecology.

The species grows in humid and open rocky slopes. It is currently known from the three localities in southwestern and central China.

Phenology.

Flowering observed from May to July.

Etymology.

The species epithet, ‘ fanjingshanensis ’, originates from one of its type localities, Fanjingshan Mountain.

Paratypes.

• China. Guizhou Province, Tongren City, Fanjingshan Mountain, near the summit; ca. 2200 m; 24 July 1941; s. coll. 967 (PE!). • China. Guizhou Province, Tongren City, Fanjingshan Mountain, near the summit; ca. 1650 m; 4 May 1959; Qianbei Expedition 654 (NAS!). • China. Guizhou Province, Tongren City, Fanjingshan Mountain, near the summit; ca. 1650 m; 4 May 1959; T. P. Zhu & Z. F. Liu 654 (KUN!). • China. Guizhou Province, Tongren City, Fanjingshan Mountain, near the summit; 2269.9 m; 22 July 2016; D. W. Lu 522222160722022 LY (GZTM!). • China. Guizhou Province, Tongren City, Fanjingshan Mountain, near the summit; ca. 2200 m; 9 June 2023; G. X. Hu in N. Wei 1 (HIB!). • China. Hubei Province, Yichang City, Changyang Tujia Autonomous County, Chuankongdong Cave, 30.3858 ° N, 110.6761 ° E; ca. 400 m; 28 May 2025; C. J. Zhou Q 20250528 (HIB!). • China. Shaanxi Province, Langao County; ca. 2300 m; 19 July 2008; Bashan Collecting Team 1838 (PE!).

Conservation status.

Euphorbia fanjingshanensis is given a preliminary assessment of Least Concern (LC). The species is currently known from three localities in China: Fanjingshan in Guizhou, Chuankongdong Cave in Changyang, Hubei, and Langao in Shaanxi. A quick evaluation using GeoCAT indicates an Area of Occupancy (AOO) of ca. 12 km 2 and an Extent of Occurrence (EOO) of approximately 31,385 km 2. Although the distribution is relatively restricted, all known populations occur within protected areas or intact montane habitats, with stable population sizes and no observed major threats. Therefore, the species is currently assessed as LC under the IUCN Red List criteria. (IUCN 2001).