塔藓科 ta xian ke
by Jia Yu, Wang Mei-zhi, and Wang You-fang
Plants medium-sized to large, stiff, robust, rarely slender, green, yellowish green to yellow, often slightly glossy, in loose or dense wefts. Stems prostrate, sometimes reddish; secondary stems usually erect-spreading, sometimes arcuate-curved, irregularly branched or regularly 2–3 pinnately branched, usually exhibiting a sympodial or monopodial growth pattern; in cross section a central strand present, with large parenchyma and small epidermis cells; branched paraphyllia or foliose pseudoparaphyllia often present on stems and branches, paraphyllia lacking in some genera and species; rhizoids usually brownish. Leaves in several ranks, spirally imbricate-arranged; stem leaves usually differentiated from branch leaves, erect-spreading, squarrose-recurved or falcate-secund, clasping at base; ovate-lanceolate, broadly lanceolate or triangularly cordate, sometimes plicate or rugose, rarely concave, acuminate, acute to obtuse; upper leaf margins usually toothed, sometimes slightly reflexed at base; costae single, double or irregularly forked, strong or weak, extending to the middle of leaf or vanishing below the middle, rarely absent; laminal cells linear or elongate-vermiform, length and width approximately 5–16:1, smooth, papillose or prorate at back, slightly incrassate or thin-walled; basal cells slightly broad, sometimes yellowish, slightly pitted; alar cells differentiated, usually short, quadrate or subquadrate. Dioicous. Perigonia bud-like, scattered on stems and branches. Perichaetia restricted on the stems, perichaetial leaves usually not plicate, costae double, short, inner perichaetial not costate. Setae elongate, brownish red, smooth; capsules ovoid or elongate-ovoid, suberect to horizontal or pendent; apophyses rarely present; exothecial cells sometimes slightly incrassate, stomata superficial, present at base; annuli of 1–3 rows of differentiated cells or absent; opercula shortly conic, rostrate; peristome double; exostome teeth deeply colored, narrowly lanceolate, lightly bordered; outer surface cross-striate, usually finely and densely papillose; endostome segments lanceolate, light yellow; basal membrane high, usually smooth, trabeculate, perforated along median line; cilia 1–4, sometimes absent. Calyptrae cucullate, smooth. Spores spherical, 8–25 µm in diameter, rarely up to 50 µm, yellowish, finely papillose or nearly smooth.