Plants on rock, forming loose festoonlike mats or rarely compact mats. Stems radially symmetric, long-creeping, short-creeping, or pendent, not readily fragmenting, irregularly forked, without budlike arrested branches, tips straight; main stem indeterminate, lateral branches determinate, spreading, 1--2-forked. Rhizophores borne on upperside of stems, throughout stem length, 0.15--0.27(--0.3) mm diam. Leaves monomorphic, in alternate pseudowhorls of 4 (on main stem and older lateral branches) or 3 (on young lateral branches and secondary branches), loosely appressed, ascending, green, linear to linear-lanceolate or narrowly triangular-lanceolate, (2--)2.5--3.4 X 0.45--0.5(--0.7) mm; abaxial ridges prominent; base mostly cuneate and decurrent, rarely rounded and adnate (on young branches), pubescent or glabrous; margins entire to denticulate or very short-ciliate, cilia transparent, scattered, mostly ascending, dentiform toward apex, 0.02--0.07 mm; apex keeled, slightly attenuate, short- to long-bristled; bristle transparent greenish to greenish-yellowish, rarely white, smooth, seldom slightly puberulent, sometimes breaking off, 0.25--0.7(--1) mm. Strobili sometimes paired, 0.5--3.5 cm; sporophylls lanceolate to ovate-lanceolate, abaxial ridges prominent, base glabrous, with prominent auricles (no other species has such prominent auricles), margins entire or very short-ciliate to denticulate, apex keeled, short- to long-bristled.
