Asplenium latipinnulum H. Ding & K. W. Xu 2025, sp. nov.

Asplenium latipinnulum H. Ding & K.W.Xu, sp. nov. (Figure 1) Type: — China, Fujian Province, Nanping City, Wuyishan National Nature Reserve, Feicuigu, 27°38′46.5″N, 117°56′8.54″E, elevation ca. 1600 m, 1 Sep. 2022, XKW 830 (holotype: NF!, isotypes: NF!). Diagnosis:— Asplenium latipinnulum resembles A. austrochinense in having triangular to lanceolate fronds, 2-pinnate and leathery laminae, adaxially green and sulcate stipes, and subopposite to alternate pinnae. However, A. latipinnulum differs most distinct in its dark brown to black abaxial stipes; those of A. austrochinense are dark purplish to grayyellow. Additionally, A. latipinnulum has larger fronds, with laminae up to 40 cm long and 18 cm wide, and 20–25 pairs of pinnae, whereas A. austrochinense has laminae up to 26 cm long and 10 cm wide, and 10–14 pairs of pinnae. Plant epilithic or terrestrial (Fig. 1A, B). Rhizomes short, erect, densely covered with scales. Rhizome scales long lanceolate, with long filiform apices, 4.5–6.5 mm long, 0.5–0.8 mm wide, reddish brown, clathrate (Fig. 2A). Fronds up to 60 cm long (Fig. 1B). Stipes 15–25 mm long, semiterete, dark brown to black, base sparsely covered with scales (Fig. 1F). Rachises dark brown to stramineous, sparsely covered with fibrous scales, scales hair-like, occasionally with a small triangular base, to ca. 2 mm long (Fig. 1C). Laminae 2-pinnate, triangular to lanceolate, 30–40 cm long, 10–18 mm wide, base cuneate to truncate, apex acute-acuminate, glossy dark green adaxially, pale green abaxially, glabrous (Fig. 1C). Pinnae 20–25 pairs, subopposite to alternate, stalk ca. 5 mm, basal pinnae not reduced, narrowly triangularlanceolate, 4.5–8 × 1.5–2.5 cm, apex acute, 1-pinnate (Fig. 1C); pinnules 4–8 pairs, anadromous, basal acroscopic pinnule largest, free or adnate to costa, usually rhombic, 1.8–2.5 × 0.5–1.2 cm, apex obtuse-truncate to subacute, basal pinnule simple to pinnatifid and with 2 or 3 segments, base decurrent on costa in upper pinnae, margin serrate, teeth usually obtuse or acute (Fig. 1D, G). Veins obvious abaxially, obscure but occasionally raised adaxially, veins not reaching margin, anadromous (Fig. 1E). Sori 2–5 per pinnule, linear, 4–7 mm (Fig. 1E); indusia pale brown, linear, firm, membranous, entire, opening toward costule or costa, persistent (Fig. 1E). Distribution & Habitat:— Asplenium latipinnulum is known only from Wuyishan, Nanping, China. Currently, only one large population with more than 50 individuals was found. It grows in a shady area on large rocks in the forest, at an elevation of ca. 1600 m. Etymology:—The specific epithet refers to the broad shape of the pinnae. Vernacular name:—kuò yǔ tiě jiǎo jué (Ȑfiữffl̎; Chinese name). Comments:—In the type locality of the new species, at least four Asplenium species were found, including A. normale D. Don, A. wilfordii, A. yoshinagae and the new species A. latipinnulum. Of the four species, three (A. wilfordii, A. yoshinagae, and A. latipinnulum) are members of the A. austrochinense subclade (Xu et al. 2020).