19. Platygyrium Schimp. in B.S.G. 平锦藓属 ping jin xian shu
Bryol. Eur. 5: 95 (fasc. 46–47 Mon. 1). 1851, nom. cons.
Plants small, green or yellowish brown, glossy, in loose mats. Stems creeping, irregularly branched, rhizoids numerous; branches short, densely foliate. Stem leaves and branch leaves similar, more or less appressed or somewhat imbricate when dry, erectopatent when moist, ovate-lanceolate to oblong-lanceolate, somewhat decurrent at base, shortly acuminate at apex; margins entire, reflexed below; costae double, very short or indistinct; leaf cells smooth, rhomboidal, apical cells short; alar cells differentiated, in a small group of quadrate cells. Brood bodies usually abundant in the axils of leaves. Dioicous. Inner perichaetial leaves slenderly lanceolate, somewhat sheathing at base. Setae slender, purplish red, smooth; capsules erect, symmetric, cylindrical; annuli well developed, broad, in 2–4 rows of cells, opercula conic, shortly obliquely rostrate; persistent; peristome double; exostome teeth narrowly lanceolate, yellowish brown, distinctly bordered, transversely striolate-papillose (not clearly striolate) at the base on dorsal surface, moderately trabeculate on the ventral surface; endostome segments linear-lanceolate, yellowish, smooth, keeled; basal membrane very low or absent; cilia lacking. Calyptrae cucullate, smooth, naked. Spores small, yellowish, minutely papillose.