1. Isopterygium albescens (Hook.) Jaeg. 淡色同叶藓 dan se tong ye xian
Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1876–77: 433. 1878. Hypnum albescens Hook. in Schwaegr., Sp. Musc. Frond., Suppl. 3, 1(2): 226b. 1828. Type: Sikkim.
Isopterygium expallescens Levier in S. Okamura, J. Coll. Sci. Imp. Univ. Tokyo 36(7): 36. 1915, nom. nud. Isopterygium expallescens Levier ex His., Classif. Moss Jap. 85. 1932.
Plants slender, pale green, often silver-white, glossy. Stems flattened; pseudoparaphyllia filamentous. Leaves rounded ovate or ovate-lanceolate, gradually or suddenly acuminate, ending with filiform apices, ca. 1.20 mm × 0.25 mm, concave; margins serrulate above; costae double, short or indistinct; upper and median leaf cells linear, 65–80 µm × 3.5–4.0 µm, thick-walled; basal cells shorter and broader, brownish, thick-walled; alar cells not distinctly differentiated. Autoicous or dioicous. Inner perichaetial leaves ca. 2 mm long, acuminate at apex. Setae 15–20 mm long, 0.15 mm thick, reddish brown; capsules horizontal to inclined, oblong-ovoid, 1.3–1.5 mm × 0.6–0.7 mm, with long neck, brownish; peristome hypnoid, with 2 cilia. Spores 8–10 µm in diameter, mostly papillose.