Lepisorus angustifrons Tagawa.

Plants 10-20 cm tall. Rhizomes slender and decumbent, wirelike, ca. 1 mm in diam., densely scaly; scales appressed, deep brown, narrowly lanceolate, 2-4 × 0.4-0.8 mm, basifixed with a tuft of hairs on point of attachment, base broadly ovate, upward attenuate, margin shortly serrate, apex extended into long awn; lumina large, isodiametric, middle ones subrectangular, walls slightly thickened. Fronds remote; stipe brown, 1.2-5(-12) cm; lamina brown on both surfaces when dried, linear-lanceolate, 10-20 × 0.3-1 cm, widest at middle, papery, with a few scattered scales, leaf scales with transparent oblong lumina, lamina base cuneate, decurrent, margin flat and straight or slightly revolute, apex shortly acuminate; costa raised on both sides, veinlets obscure. Sori along lower 1/3 of laminae, midway between costa and margins or nearer costa, elliptic; paraphyses brown, suborbicular, 0.3-0.4 mm in diam.; lumina large, subsquare, transparent.

Lepisorus pseudoussuriensis is most closely related to the preceding species, L. ussuriensis. They can be distinguished easily by the paraphyses, the former has these with square transparent lumina, which are very rare in this genus. These two species also have different distributions.

● On tree trunks or moss-covered rocks in forests; 1000-3000 m. Taiwan.