10. Pterobryon Hornsch. 蕨藓属 jue xian shu
Fl. Bras. 1(2): 50. 1840. Pilotrichum sect. Pterobryon (Hornsch.) Müll. Hal., Syn. Musc. Frond. 2: 179. 1851.
Plants usually robust, green, light yellowish, or yellowish brown, in dense tufts or mats. Primary stems prostrate, with dense, brownish rhizoids; secondary stems dendroid or pendulous, sparsely foliate, with squarrose leaves at the base, densely and irregularly pinnately branched above, often with erect-spreading branches and densely foliate, somewhat complanate, obtuse at branch tips. Leaves of upper secondary stems and mature branches erect-spreading, oblong-ovate or ovate-lanceolate, slightly concave, strongly plicate, shortly or long acuminate at the apex; margins usually serrate above; costae single, ending near the apex; leaf cells narrowly hexagonal to linear-rhomboidal or linear, moderately thick-walled, smooth, weakly porose; basal leaf cells lax, brown; alar cells more or less differentiated. Dioicous. Inner perichaetial leaves ovate-lanceolate, sheathing at the base, abruptly acute or narrowly long acuminate at the apex. Setae very short; capsules immersed, usually ovoid, brown; opercula low conic, with a short and straight beak; peristome double or sometimes with endostome poorly developed, rarely a prostome present; exostome teeth pale yellow, narrowly lanceolate, smooth, median line indistinctly zigzagged; endostome segments often attached to the teeth, thin, hyaline; basal membrane very low or absent; cilia absent. Calyptrae small, mitrate, smooth. Spores spherical, finely or densely papillose.