2. Bartramia Hedw. 珠藓属 zhu xian shu
Sp. Musc. Frond. 164. 1801.
Exodokidium Card., Wiss. Erg. Schwed. Sudpolar-Exp. 4(8): 226. 1908.
Glyphocarpa R. Brown, Trans. Linn. Soc. London 12: 575. 1819, nom. illeg.
Plants small, medium-sized to large, green to grayish blue, in dense tufts. Stems erect, simple or branched, sparsely or densely radiculose, with leaves in 8 ranks; central strand well developed. Leaves loosely or closely arranged, erect or crisped when dry, ovate-lanceolate to linear-lanceolate, often sheathing at base, slender toward apex; margins serrate above, bistratose in the upper part; costae single, strong, dentate at back, percurrent or excurrent; median and upper leaf cells small, thick-walled, quadrate, papillose or mammillose at both cell ends; cells in sheathing base rectangular, thin- to somewhat thick-walled, hyaline, smooth; alar cells weakly differentiated. Synoicous or dioicous. Perichaetia terminal or lateral by innovations. Setae short or often elongate, straight or curved; capsules nearly spherical, inclined or curved, oblique at mouth, furrowed when dry; neck not developed; opercula small, conic at base, shortly apiculate; peristome double, rarely single or absent; exostome teeth narrowly triangular, with a median zigzag line, papillose below, trabeculate on the inner surface; endostome segments well developed, perforate; basal membrane high or low; cilia rudimentary or absent. Calyptrae cucullate, smooth. Spores kidney-shaped or spherical, finely to coarsely papillose.