7. Orthodontium Schwaegr. 直齿藓属 zhi chi xian shu
Sp. Musc. Frond., Suppl. 1, 2(2): 123. 1826.
Plants small, green, yellowish green or yellowish brown, not or slightly glossy, in loose or dense tufts. Stems erect, simple, branched or branched from the base, with dense rhizoids at base. Leaves erect, curved or twisted when dry, erect-spreading when moist, keeled, narrowly lanceolate, linear or narrowly ovate-lanceolate; margins plane, entire or serrulate near the apex; costae ending below the apex or percurrent; leaf cells linear, linear-hexagonal or narrowly hexagonal. Autoicous or synoicous. Setae slender or rather short, yellowish; capsules erect or suberect, symmetric, brown or yellowish brown, ovoid, ovoid-pyriform or nearly elongate-ovoid; neck distinctly developed or sometimes short, smooth or irregularly grooved; exothecial cells thin-walled; opercula often conic, obliquely long-rostrate; annuli absent; peristome double; exostome teeth slender or short and broad, yellowish brown or hyaline, smooth or papillose; endostome segments narrowly lanceolate, as long as the teeth or shorter, smooth or papillose; basal membrane low or absent; cilia absent. Calyptrae cucullate. Spores spherical, papillose.