Bryologist 5: 65. 1902.
Plants small, green to golden yellow, glossy. Stems 2–3 cm, branches ascending. Leaves erect to erect-spreading, sometimes homomallous, oblong-lanceolate, tapering gradually to apex, 1–1.5 mm; margins reflexed; apex gradually acuminate; alar cells enlarged, inflated, yellow, in 1 row, supra-alar cells several in 2 rows, quadrate to short-rectangular; laminal cells long-rhomboidal. Specialized asexual reproduction rare, by axillary propagula, 1-seriate, rough, branched or unbranched. Seta 0.4–0.8 cm. Capsule erect, 1 mm.
Phenology: Capsules mature fall.
Habitat: Logs, bark of tree bases, rock, swamps
Elevation: low to moderate elevations
Ala., Calif., Ga., La., N.Y., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va., Mexico, Central America, South America.
Sematophyllum adnatum resembles Pylaisia (Hypnaceae) in habit, but is distinguished by its strongly differentiated, elongate (not isodiametric) alar cells. The species is introduced in California.