5. Tortula planifolia X.-J. Li, Acta Bot. Yunnan. 3:109. 1981.
Plants small, less than 10 mm high, dark green above, reddish brown below, in loose tufts. Stems erect, usually irregularly branched, radiculose below. Leaves contorted-curved when dry, spreading when moist, oblong-obovate or spathulate, rounded-obtuse, somewhat sheathing at base; margins plane, entire or crenulate by projecting papillae, borders indistinct; costa slender, excurrent, ending in a short, smooth, hyaline awn; upper leaf cells quadrate to hexagonal, thin-walled, each cell covered by several C-shaped papillae; basal cells sharply differentiated, rectangular, hyaline, mostly smooth. Autoicous. Setae ca. 5 mm long; capsules erect, cylindrical; peristome teeth filiform, twisted, densely papillose, with low or high basal membrane. Spores yellowish, smooth.
Type. China: Xizang, Long-zi Co., Zhun-ba, M. Zang 1042a (holotype HKAS).
Specimens examined: XINJIANG: Yi-wu Co., J.-C. Zhao 4289a (HKAS). XIZANG: Long-zi Co., M. Zang 1043a, 1059 (HKAS).
Habitat: on rocks; Distribution: endemic to China.
Illustrations: Pl. 133, figs. 4–6.