19. Taxithelium Spruce ex Mitt. 麻锦藓属 ma jin xian shu
J. Linn. Soc. Bot. 12: 21, 496. 1869.
Plants slender or somewhat robust, green, yellow or grayish, not glossy or slightly glossy, in interwoven mats. Stems elongate, prostrate, with loose rhizoids, often regularly branched; branches short, complanate, slightly blunt or attenuate at apex; paraphyllia absent. Leaves in numerous ranks, appressed, slightly concave, ventral and dorsal leaves smaller, lateral leaves larger, slightly asymmetric, rounded ovate or oblong-ovate, shortly acuminate, or ovate-lanceolate, shortly or long piliform at apex; margins serrulate, sometimes serrate above, rarely entire; costae absent; leaf cells narrowly rhomboidal, multipapillose, or prorate, rarely nearly smooth; basal cells shorter, loosely arranged; alar cells clearly differentiated. Autoicous or dioicous. Inner perichaetial leaves erect, ovate or ovate-lanceolate, acute or acuminate at apex; margins weakly serrulate. Setae slender, elongate, mostly smooth; capsules ovoid, slightly inclined, arcuate, apophysis short, constricted below the mouth; opercula conic, slightly acute or obtuse at tips; annuli persistent; peristome double; exostome teeth fusing at base, lanceolate above, yellowish brown, cross-striate below, hyaline and papillose above on outer surface, trabeculate on inner surface; endostome segments broadly lanceolate, papillose, keeled, perforate along the median line; basal membrane high; cilia often 1, rarely 2, usually shorter than segments. Spores irregularly spherical, brownish, smooth.