Hymenasplenium wangpeishanii Li Bing Zhang & K.W. Xu, 2018

Xu, Ke-Wang, Zhang, Liang, Lu, Ngan Thi, Zhou, Xin-Mao, He, Hai, Luong, Thien Tam, Knapp, Ralf, Liao, Wen-Bo & Zhang, Li-Bing, 2018, Nine new species of Hymenasplenium (Aspleniaceae) from Asia, Phytotaxa 358 (1), pp. 1-25 : 22-23

Hymenasplenium wangpeishanii Li Bing Zhang & K.W. Xu , sp. nov. Fig. 15 .

Type:— CHINA. Guizhou: Puding, Chengguan Zhen, Lianhua Dong, Dahua Dong , elev. 1250 m, 26°20’45”N, 105°47’27”E, in a cave, 7 August 2017, Li Bing Zhang, Yi-Fan Duan & Matthias Kropf 9610 (holotype CDBI!) .

Diagnosis:— Hymenasplenium wangpeishanii is most similar to H. murakami-hatanakae in having pinnae falcate to trapeziform, marginal teeth acute, but the former has sori near costa or submedial, while the latter has sori supramedial to (sub)marginal.

Plants perennial, evergreen, up to 45 cm tall. Rhizomes long creeping, ca. 3 mm in diam., apex densely scaly, scales dark brown, narrowly triangular or lanceolate, margins nearly entire, 1–1.5 × 0.4 mm; root dark brown when dried, up to 5 cm long, ca. 0.4 mm diam, rhizome and root covered with yellowish brown woolly indument. Fronds remote, up to 12 mm apart, herbaceous; petioles dull brown, base sparsely covered with scales and yellowish brown woolly indument, scales 0.7 × 2–3 mm, lanceolate, brown, margins nearly entire. Laminae narrowly ovate, 1-pinnate, 25–30 × 5–7 cm, base deflexed, slightly reduced, widest near middle, gradually narrowing toward apex, apex acuminate; rachises 1 mm in diam., subglabrous, brown, adaxial side grooved and with 2 green narrow wings. Pinnae shortly stalked to almost sessile at apex, 20–30 pairs, subopposite near base and alternate in the middle and apex, falcate to trapeziform, (middle pairs) 2–3.5 × 0.7 cm, about 3 mm apart, base asymmetrical, acroscopic side truncate and subparallel or forming an angle less than 15° with rachis, basiscopic side cuneate, with 10 mm absent (calculated from the base to the first tooth appearing in the margin of basiscopic side), acroscopic margins serrate, teeth not retuse, acute, basiscopic margins entire at base, serrate in the middle and apex; pinna apex acute. Veins visible on both sides of pinnae, stramineous, lateral veins visible on both sides of pinnae, green, forking and terminating in marginal teeth, 2 basal basiscopic veins lacking. Sori linear, 1–3 mm long, near costa or submedial, (2–)6–8(–10) on acroscopic side and 3–6 on distal basiscopic side of the pinnae in the middle part of the laminae, centers 1–2 mm apart from one another; indusia brown, linear, membranous, entire, indusium of the second sorus on the acroscopic side of pinnae opening toward rachis, others opening toward costa.

Geographical distribution:— Hymenasplenium wangpeishanii is mainly only known from Guizhou and Sichuan, Southwest China.

Ecology:— Hymenasplenium wangpeishanii was observed to grow inside a limestone cave with humid and shady conditions.

Etymology:—The species epithet is in honor of Prof. Pei-Shan Wang for his great contributions to the pteridology in China, especially in Guizhou (e.g., Wang & Wang 2001).

Vernacular name:— áěůďäffǎ (pei shan mo ye tie jiao jue).

Taxonomic notes:— Hymenasplenium wangpeishanii is also similar to H. apogamum in the sorus distribution and the indusia opening direction, but the former has pinnae falcate to trapeziform and marginal teeth of the pinnae deep (1 mm), while the latter has pinnae quadrangular-trapeziform and marginal teeth of the pinnae shallow (0.3–0.7 mm). In addition to the differences from H. murakami-hatanakae and H. apogamum , the new species is also morphologically similar to and phylogenetically closely related to H. speluncicola in the limestone habitat, but the new species has petioles slender (ca. 1 mm in diam.), while H. speluncicola has petioles robust (ca. 2 mm in diam.).

Figures

FIGURE 15. Hymenasplenium wangpeishanii Li Bing Zhang & K.W. Xu, sp. nov.—A. Habit.—B. Portion of abaxial lamina.