3. Trichostomum hattorianum B. C. Tan & Iwats. 卷叶毛口藓 juan-ye mao-kou xian
J. Hattori Bot. Lab. 74: 393. 1993. Trichostomum involutum Broth., Akad. Wiss. Wien Sitzungsber., Math.-Naturwiss. Kl., Abt. 1, 131: 210. 1923, hom. illeg. Type. China: Guizhou (Kweitschow), Li-ping, Handel-Mazzetti 10994 (holotype H).
Plants small, 10–15 mm high, yellowish green to light brown, in dense tufts. Stems erect, simple or irregularly branched, densely foliate. Leaves strongly crisped when dry, erecto-patent when moist, fragile, linear-lanceolate, ca. 5 mm long, acuminate or setaceous, weakly sheathing at base; margins entire, strongly incurved in the upper half; costa stout, excurrent as an apiculus; upper leaf cells rounded-quadrate, moderately thick-walled, green and obscure, each cell with several large, circular papillae on both surfaces; basal cells slightly elongate, irregularly short-rectangular, smooth, yellowish or hyaline. Sporophytes not seen.