5. Atractylocarpus Mitt., J. Linn. Soc., Bot. 12: 71. 1869.
Metzleria Schimp. ex Mild., Bryol. Siles. p. 75. 1869, nom. rejic. Metzleriella Limpr., Laubm. Deutschl. 1: 411. 1887, nom. inval. prov. Metzlera Schimp. ex Hag., Kongel. Norske Vidensk. Selsk. Skr., 1910(3): 15. 1910. Metzlerella Hag., Kongel. Norske Vidensk. Selsk. Skr., 1914(1): 62. 1915.
Plants small, slender to large, usually less than 2 cm high, sometimes up to 5 cm high, dull, yellowish green, glossy, in loose or compact tufts. Stems erect, simple or sparsely branched, radiculose nearly to the apex; central strand present. Leaves erect-spreading or slightly falcate-secund, narrowly ovate-lanceolate at base, subulate to tubulosely setaceous above; margins entire or only serrulate near the apex, often recurved; costa single, broad, flattened, 1/2 – 2/3 the leaf base width, filling most of leaf subula, in cross section with 2 stereid bands and a median row of guide cells; marginal borders consisting of linear cells; upper cells linear, thick-walled; lower cells rectangular, thin- to thick-walled; alar cells not differentiated. Autoicous or dioicous. Perigonia with a short stalk. Perichaetial leaves convolute-sheathing, abruptly subulate. Setae elongate, straight; capsules erect, symmetric or sometimes slightly curved, narrowly oblong-cylindric; annuli none or large, deciduous; opercula long-rostrate; peristome teeth divided nearly to the base, coarsely papillose above, diagonally or vertically striate below. Calyptrae cucullate, somewhat inflated, entire at base, smooth. Spores spherical.
Atractylocarpus consists of nine species worldwide (Padberg and Frahm 1985). One species is currently known from China.
