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.
Logs, bark of tree bases, rock, swamps. 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.