1. Callicladium haldanianum (Grev.) Crum 拟腐木藓 ni fu mu xian
4: 1177. 1923. Hypnum haldanianum Grev., Ann. Lyceum Nat. Hist. New York. 1: 275. f. 23. 1825. Type: Canada.
Callicladium haldanianum (Grev.) Crum var. viride (Okam.) Iwats. & Nog., J. Jap. Bot. 48: 215. 1973. Stereodon haldanianus var. viridis Okam., J. Coll. Sci. Imp. Univ. Tokyo, 36(7): 34. pl. 17. 1915.
Plants medium-sized, bright-green to yellowish or brownish, in extensive, flattened mats. Stems creeping, irregularly branched; branches rather short and unequal, mostly flattened, tapered; pseudoparaphyllia foliose. Stem leaves and branch leaves similar, crowded, erect to erect-spreading, usually homomallous, somewhat complanate, concave, clearly asymmetric, more or less keeled, ovate-lanceolate, gradually narrowed to a short to rather long acumen, 1.0–1.6 mm × 0.5–0.6 mm; margins plane, entire; costa very short, double or sometimes indistinct; median and upper leaf cells linear, smooth, flexuose; lower cells shorter and broader; alar cells clearly differentiated, excavate, usually yellowish brown, quadrate to subquadrate, moderately thick-walled. Autoicous. Perichaetial leaves long-subulate and sheathing at base. Setae elongate, 1.5–3.0 cm long, smooth; capsules long-cylindrical, 1.5–3.0 mm long, asymmetric, suberect from the base and somewhat curved near the mouth; annuli slightly differentiated; opercula shortly obliquely rostrate; peristome double; exostome teeth narrowly lanceolate, cross-striolate below, bordered, trabeculate on the ventral surface; endostome segments slenderly lanceolate, keeled; basal membrane high; cilia single. Calyptrae cucullate, smooth. Spores spherical, 12–15 µm in diameter, finely papillose.