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

Hymenasplenium perriei Li Bing Zhang & K.W.Xu View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 ).

This species is most similar to H. murakami-hatanakae Nakaike (1992: 841) in having laminae acuminate, pinnae falcate to trapeziform, and usually pointing upward, and pinna apex usually acuminate or rarely acute, but it has phyllopodia usually 2–3(–10) mm apart, sori inframedial, marginal teeth usually with notches, and veins usually terminating in marginal teeth below the notch, while H. murakami-hatanakae has phyllopodia ca. 10 mm apart, sori supramedial to (sub)marginal, marginal teeth entire, and veins terminating in teeth.

Type:— FIJI. Viti Levu: Namaosi, Namosi end of Nabukavesi-Namosi Road, Wainitunikadua Creek , elev. 350 m, 18°3’24”S, 178°9’24”E, in very shaded and wet rocks above stream, 30 August 2011, Perrie et al. Fiji 2011 13 (holotype WELT-P023745 !) GoogleMaps .

Plants perennial, evergreen, up to 30 cm tall. Rhizomes creeping, ca. 3 mm diam., apex densely scaly, scales dark brown, lanceolate, margins erose to entire, 1–2 × 0.1–0.5 mm; roots dark brown when dried, robust, up to 10 cm long, slender, ca. 0.5 mm in diam, rhizomes and roots glabrous or covered with brown floccose indument. Phyllopodia distinct, 2–3(–10) mm apart. Frond grayish green when dry, green when fresh, herbaceous; petioles brown, 5–12 × 0.05– 0.01 cm, subglabrous, base sparsely scaly. Laminae narrowly ovate, 1-pinnate, 10–18 × 3–6 cm, base not deflexed, slightly reduced, widest near middle, gradually narrowing toward apex, apex acuminate; rachises 0.5 mm in diam., glabrous, brown, adaxial side grooved and with 2 green narrow wings. Pinnae shortly stalked and upper pinnae often subsessile, 15–20 pairs, alternate, falcate to trapeziform, (middle pairs) 2–3 × 0.4–0.5 cm, about 3–4 mm apart, base asymmetrical, acroscopic side truncate and subparallel or forming an angle less than 30° with rachis, basiscopic side excavate over half of the length of the pinna, acroscopic margins irregularly serrate, teeth usually retuse, acute or obtuse, basiscopic margins entire at base, irregularly serrate in the middle and apex; pinna apex acuminate or acute. Costae visible on both side of the lamina, base usually brown and turn into pale green towards the apex, veins visible on both side of the lamina, pale green, forking and usually terminating below the tooth notches or more rarely below marginal teeth, 3–4 basal basiscopic veins lacking. Sori linear, (2–) 3–4 mm long, near costa or submedial, 3–5 on acroscopic side and 2–3 on basiscopic side of the pinnae, centers ca. 1.5 mm apart from one another; indusia brown, linear, membranous, entire, opening toward costa.

Geographical distribution:— Hymenasplenium perriei is currently only known from southeastern Fiji, Pacific regions.

Habitat:— Hymenasplenium perriei was observed to grow on very shaded and wet rocks above stream, along with bryophytes.

Etymology:—The species epithet is in honor of Leon Perrie, based at the Museum of New Zealand, Te Papa Tongarewa, Wellington, for his contributions to the pteridology in Oceania. He also collected the type of this new species.