白齿藓科 bai chi xian ke
by Zhang Man-xiang and Si He
Plants slender to robust, green to yellowish green, often glossy, in loose or dense tufts or mats. Stems creeping, usually with brownish rhizoids; secondary stems erect or ascending, or curved, rarely pendulous, mostly simple, more or less julaceous, sometimes branched; paraphyllia absent; pseudoparaphyllia sometimes present; in cross section central strand present or absent. Leaves appressed when dry, erect-spreading when moist, sometimes secund, cordate-ovate or oblong-ovate, shortly to long-acuminate at the apex; margins plane, entire or serrulate near the apex, plicate or not plicate; costae single, short, or absent; leaf cells thick-walled, smooth; upper cells rhombic, gradually elongate toward the base; alar cells differentiated, consisting of a large group of oblate-rectangular or shortly rectangular cells. Dioicous. Inner perichaetial leaves large, sheathing at the base. Setae short, sometimes elongate; capsules mostly symmetric, erect, ovoid, oblong-ovoid to cylindrical; opercula conic, often obliquely rostrate; annuli usually differentiated; stomata often absent; peristome double or single; exostome teeth yellow or hyaline at the tips, lanceolate or linear-lanceolate, papillose, rarely cross-striolate at the base; endostome segments often reduced or sometimes absent; basal membrane low; cilia absent. Calyptrae cucullate, smooth or sparsely hairy. Spores spherical, finely papillose.