5. Okamuraea Broth. 褶藓属 zhe xian shu
Öfvers. Förh. Finska Vetensk.-Soc. 49(10): 2. 1906.
Rigodiopsis Dix. & Thér., Rev. Bryol., n. ser. 4: 155. 1933.
Plants green to yellowish green, slightly shiny, in mats. Primary stems creeping, with fascicular rhizoids; irregularly or fascicularly branched; branches rather dense, erect or curved, rounded, acuminate at tips, sometimes flagelliform. Leaves loosely appressed on stems when dry, spreading when moist, ovate-lanceolate, concave, slightly decurrent, plicate at base, with an acuminate apex; margins entire, recurved at base; costa single, slender to rather thick, reaching to the middle of leaf; leaf cells rhomboidal or oblong-rhomboidal, slightly thick-walled, smooth; alar cells usually subquadrate. Dioicous. Inner perichaetial leaves smaller than stem leaves, sheathing at base, suddenly narrowed to an acuminate apex. Setae elongate, erect, reddish, smooth; capsules erect or slightly pendent, oblong-ovoid, mouth not contracted; annuli not differentiated; peristome double; exostome teeth 16, narrowly lanceolate, usually fused at base, not striate on outer surfaces, borders differentiated at both sides, densely papillose; endostome segments reduced, hyaline, finely papillose; basal membrane high; cilia lacking; opercula short, rostrate. Calyptrae with sparse hairs. Spores ovoid, densely verrucose.