5. Leptobryum(Bruch & Schimp. in B.S.G.) Wils. 薄囊藓属 bo nang xian shu
Bryol. Brit. 219. 1855. Bryum sect. Leptobryum (Bruch & Schimp. in B.S.G.) Lesq., Mem. Calif. Acad. Sci. 1: 20. 1868. Bryum subgen. Leptobryum Bruch & Schimp. in B.S.G., Bryol. Eur. 4: 1. 1851.
Plants small, soft, slender, green, in loose or dense tufts. Stems erect, simple, sparsely foliate below, sometimes with rhizoidal gemmae. Lower leaves small, distant, lanceolate; upper leaves elongate, dense, narrowly linear; margins plane, entire below, serrulate above; costae broad, filling most of the subula, ending below the apex or excurrent; leaf cells linear; basal cells long-rectangular. Autoicous or dioicous. Setae elongate, slender; capsules pyriform, pendulous, glossy; peristome double, perfect; basal membrane high; cilia present or reduced. Calyptrae cucullate, smooth. Spores spherical, minutely papillose.