沼羽藓科 zhao yu xian ke
by Si He
Plants stout to rather robust, sometimes delicate to medium-sized, dark green, yellowish green, or brownish, not glossy, or somewhat glossy, in tufts or large cushions or interwoven mats. Stems erect, ascending, or more or less prostrate, often regularly pinnately branched; central strand absent or weakly differentiated; paraphyllia multi-branched, densely spread on stems and branches, filiform-branched, lanceolate-ciliate, or lanceolate, smooth, not papillose, composed of elongate cells with oblique cell walls, ending in an acute cell; rhizoids reddish brown at lower portion of stems. Stem and branch leaves similar or polymorphic; stem leaves appressed or incurved when dry, erect-patent when moist, gradually narrowed from cordate, ovate, or triangular base to a lanceolate apex, often secund toward one side, usually longitudinally plicate; margins slightly revolute, serrate or dentate above; costae single, thick, to ca. 4/5 the leaf length; median leaf cells pellucid, oblong-rhomboidal or oblong-hexagonal, slightly prorate, thin-walled, or finely unipapillose; apical cells oblong, smooth; basal cells rectangular; branch leaves ovate-lanceolate, often abruptly narrowed toward apex. Autoicous or dioicous. Inner perichaetial leaves erect, oblong-lanceolate, often serrate, deeply plicate, costae ending below the apex. Setae elongate, 20–50 mm long, smooth; capsules inclined to horizontal, oblong-ovoid or cylindrical, slightly curved to strongly curved; opercula conic, shortly to long-rostrate; annuli usually differentiated; peristome double; exostome teeth narrowly lanceolate; endostome segments nearly as long as teeth, perforate; basal membrane rather high; cilia absent or weakly to rather well developed, nodulose. Calyptrae cucullate, smooth. Spores spherical, finely papillose.