2. HylocomiumBruch & Schimp. inB.S.G. 塔藓属 ta xian shu
Bryol. Eur. 5: 169 (fasc. 49–51 Mon. 1). 1852.
Plants medium-sized to large, stiff, yellowish green, olive-green, yellow to brownish red, dull or slightly glossy, in loose wefts. Stems prostrate, with ascending-arching innovations, usually 2–3-pinnately or -dendroidly branched, forming a sympodial growth pattern, 1–3 cm long; in stem cross section an inner collenchyma of large cells with somewhat thickened walls and an outer sterome of smaller, thick-walled cells; epidermis not differentiated; central strand absent; paraphyllia densely covering main stems and main branches, fewer on branchlets; pseudoparaphyllia not differentiated from paraphyllia. Stem leaves differentiated from branch leaves; stem leaves rounded ovate or broadly ovate at base, slightly concave, usually clasping, with long and twisted lanceolate apices, sometimes shortly acute; slightly constricted at base, sometimes slightly reflexed; margins usually toothed, sometimes subentire; costae double, unequal, separated at base, extending to ca. 1/2 the leaf length; sometimes very short or weak; laminal cells irregularly linear, length to width ratio approximately 7–12:1, thin-walled or slightly incrassate, slightly pitted, clearly papillose or prorate at back; basal cells somewhat shorter and broader, yellowish brown, incrassate, usually weakly pitted; alar cells not differentiated; branch leaves small, ovate-lanceolate or ovate, sometimes strongly concave, with short apices, lanceolate or obtuse; margins toothed or entire, costae double or indistinct. Dioicous. Inner perichaetial leaves narrowly ovate-lanceolate. Setae slender, reddish brown, sometimes slightly twisted; capsules ovoid, inclined to slightly pendent, usually with apophyses; stomata at base of capsules; annuli differentiated, with 1–2 rows of larger cells; peristome double; exostome teeth narrowly lanceolate, yellowish brown, with a light-colored border, papillose above, fusing at base; outer surface cross-striate; endostome segments lightly yellow, smooth; trabeculate, numerous perforations along median line; basal membrane high; cilia 2–4, nodulose above. Calyptrae conic, obliquely rostrate. Spores small, 10–18 µm in diameter, yellow, finely papillose.