Pternopetalum shunhuangensis W. Zhou & L. Wu, 2025

Zhou, Wei, Feng, Zi-Lin, Tang, Long-Ping, Deng, Du, Wu, Bao-cheng & Wu, Lei, 2025, Pternopetalum shunhuangensis (Apiaceae), a new species from Hunan, China, PhytoKeys 253, pp. 261-270 : 261-270

Pternopetalum shunhuangensis W. Zhou & L. Wu sp. nov.

Type.

China • Hunan Province, Yongzhou City, Dong’an County, Hunan Dong’an Shunhuang Mountain National Nature Reserve , on rocks densely covered with moss in forests, at an altitude ca 1600 m a. s. l., 23 Apr. 2024, Lei WU, Yan-Jie Yang, Zi-Lin Feng SHS 0001 (holotype NAS) ; 19 July 2024, Lei WU, D. Deng, Zi-Lin Feng SHS 1749 (paratype CSFI) .

Etymology.

The species epithet is derived from the type locality, Shunhuang Mountain. Its Chinese name is given as 舜皇囊瓣芹 [Pinyin: shùn huáng náng bàn qín].

Diagnosis.

Pternopetalum shunhuangensis differs from P. tanakae (Franch. & Sav.) Hand. - Mazz. by its roots without tubercles at nodes, fewer basal leaves, unelongated ultimate segments of cauline leaves, elongate styles and terminal umbels. A more detailed comparison between the two species is presented in Table 1 .

Plants 12–16 cm high. Taproot fusiform. Stem 1, erect, slender, unbranched, glabrous. Basal leaves 0–1 (2), petiolate; petioles 3–5 cm; blade ovate-triangular, 1.5–3 × 2.5–3 cm, ternate or ternate- 2 - pinnate; ultimate segments flabelliform or diamond, 3–8 × 2–7 mm. Cauline leaves 1, ternate- 2 - pinnate, petioles 0.5–4 cm; 2–4.5 × 3–6 cm, ultimate segments flabelliform or diamond, 2–5 × 2–6 mm. Umbels 1–3 cm across in flower, to 5 cm in fruit; bracts absent; rays 6–20, 1.5–2.5 cm; bracteoles 2–3; umbellules 2 - flowered; pedicels 0.2–1 mm long. Calyx teeth minute, or obsolete. Petals white, broad ovate, 1.5–1.8 × 1.2–1.5 mm; stylopodium conic; styles elongate, erect, longer than the stylopodium; stylopodium plus style ca 0.8 mm, styles ca. 0.5 mm. Fruit oblong ovoid, 2–2.5 × 1–1.5 mm; ribs filiform; vittae 1–2 in each furrow, 2 on commissure.

Phenology.

Pternopetalum shunhuangensis is flowering from April to May, and fruiting from June to July.

Additional specimens examined.

Pternopetalum shunhuangensis (paratypes): China • Hunan Province: Xinning County , 21 Oct. 1962 Lin-Han Liu 15250 ( NAS, WUK) ; Xinning County, Ziyun mountain , 9 Sep. 1984 Ziyunshan Team 301, 981 ( PE) .

P. tanakae : Japan • Silvis montis ignivomi, Fudsi Yama, Jun. 1874 Savatier 3436 (holotype P, image).

P. heterophyllum : China • Hunan Province: Xinning County, Huping mountain, 10 Jul. 1987 Hupingshan Team 1318 ( PE); Sichuan Province: Baoxing County , 7 Agu. 1936 Gui-ling Qu 3454 (holotype E, image).

P. filicinum : China • Hubei Province: Ichang City, A. Henry 6600 (isotype P, image).