2. Aulacomnium heterostichum (Hedw.) Bruch & Schimp. 异枝皱蒴藓 yi zhi zhou shuo xian
Bryol. Eur. 4: 215. t. 403. 1841. Bryum heterostichum (Hedw.) Arnott, Mém. Soc. Linn. Paris 5: 278. 1827, hom. illeg. Hypnum heterostichum (Hedw.) Web. & Mohr, Index Mus. Pl. Crypt. 3. 1803. Arrhenopterum heterostichum Hedw., Sp. Musc. Frond. 198. t. 46. fig. 1–9. 1801. Type: U.S.A.
Plants medium-sized, yellowish green, in loose tufts. Stems simple or branched, 2–3 cm high, with dense rhizoids at base. Leaves dense, not crisped when dry, oblong-ovate or broadly oblong, 1.8–3.0 mm × 1.0–1.4 mm, slightly concave, obtuse at apex, not decurrent at base, margins plane, sharply dentate in the upper half; costae strong, firm, not curved, ending just below the apex; upper leaf cells irregularly rounded, quadrate or hexagonal, thick-walled, smooth; lower cells similar; basal leaf cells at the insertion not inflated, but slightly longer, unistratose, smooth. Autoicous. Setae straight, 1.0–1.5 cm long; capsules inclined, cylindrical, 2.5–3.0 mm long, slightly curved; opercula shortly rostrate; peristome double; basal membrane ca. 1/2 the height of segments; cilia 2–4, well developed. Spores brownish, 10–15 µm in diameter, densely papillose.