5. Trachypus Reinw. & Hornsch. 扭叶藓属 niu ye xian shu
Nova Acta Phys.-Med. Acad. Caes. Leop.-Carol. Nat. Cur. 14(2): 708. 1829. Meteorium sect. Trachypus (Reinw. & Hornsch.) Mitt., Trans. Linn. Soc. London, Bot. 3: 173. 1891.
Plants usually slender, medium-sized to rather large, yellowish green or brownish green, rarely bright yellow, sometimes blackish, not glossy, in small mats. Primary stems creeping; secondary stems erect-patent or pendulous, often densely and irregularly pinnately branched or irregularly branched, sometimes with flagelliform branches. Leaves loosely appressed or erect-patent when dry, spreading when moist, ovate-lanceolate or lanceolate, weakly plicate, often twisted at the apex; margins serrulate; costae single, slender, ending at the mid-leaf or above; leaf cells rhomboidal to linear, densely papillose along the lateral walls; basal cells usually smooth. Dioicous. Setae slender, elongate, papillose; capsules ovoid or globose, erect, to ca. 3 mm long; opercula conic, long rostrate; annuli not differentiated; peristome double; exostome teeth 16, grayish green or light yellow, lanceolate, finely papillose; endostome segments shorter; basal membrane low, often absent; cilia none. Calyptrae cucullate or mitrate, densely hairy. Spores spherical, light yellow, minutely papillose.