粗肋丛本藓

Plants small, 6–10 mm high, yellowish green, in dense tufts. Stems simple or monopodial; in cross section outer cortical cells small, thick-walled, central strand absent. Leaves involuted when dry, oblong-ovate or oblong-lanceolate, 0.4–1.0 mm x 0.2–0.3 mm, obtuse or more or less acute at the apex; basal portion hardly widened and not constricted; margins flat, entire; upper and median laminal cells irregularly quadrate or more or less hexagonal, 4–12 µm x 4–8 µm, thin-walled, with round unipapillae; basal cells irregularly rectangular, 12–28 µm x 8–12 µm; abaxial superficial cells of costa above the mid-leaf linear-rectangular. Sporophytes not seen.

Type. China: Xizang (Tibet), T. Thomson 127 (holotype NY).

Chinese specimen examined: Xizang: see the type information cited above.

Habitat: on rocks in alpine regions; Distribution: endemic to China.

This species can be distinguished by its oblong-lanceolate to ovate-lanceolate leaves with obtuse apices, costa often ending below the apex, and median laminal cells with roundish papillae.

Illustrations: Pl. 108, figs. 1–10.