21. Orthotrichum obtusifolium Brid. 钝叶木灵藓 dun ye mu ling xian
Muscol. Recent. 2(2): 23. 1801. Nyholmiella obtusifolia (Brid.) Holmen & Warncke, Bot. Tidsskr. 65: 178. 1969. Stroemia obtusifolia (Brid.) I. Hagen, Kongel. Norske Vidensk. Selsk. Skr. (Trondheim) 1907(13): 94. 1903. Dorcadion obtusifolium (Brid.) Lindb., Musci Scand. 29. 1879. Type: Germany. Goettingam, Persoon s.n.
Plants small, green to yellowish green above, brown below, in dense tufts. Stems rarely branched, with sparse rhizoids at the base. Leaves erect, appressed when dry, narrowly ovate or ovate-lanceolate, 1.0–1.5 mm × 0.5–0.8 mm, rounded-obtuse; margins entire or crenulate; costae narrow, subpercurrent; upper leaf cells almost isodiametric, 14–18 µm in diameter, thick-walled, centrally unipapillose; lower cells shortly rectangular to elongate, 25–50 µm × 10–15 µm, thin-walled, smooth. Gemmae clavate or cylindrical, abundant on leaf surfaces. Dioicous. Perichaetial leaves not differentiated. Setae very short; capsules immersed or slightly emergent, oblong-ovoid or oblong-cylindrical, furrowed when dry; exothecial cells differentiated in longitudinal bands; stomata superficial; peristome double; prostome none; exostome teeth in 8 pairs, reflexed when dry, finely papillose at base, papillosely striolate near apex; endostome segments 8, linear, as long as the teeth, papillose, with a distinct median line. Calyptrae mitrate, not plicate, naked, or sparsely hairy. Spores 15–20 µm in diameter, densely and finely papillose.