Hypnum confervoides Bridel, Muscol. Recent., suppl. 2: 153. 1812; Amblystegiella confervoides (Bridel) Loeske; Amblystegium confervoides (Bridel) Schimper; A. pseudoconfervoides Kindberg; Serpoleskea confervoides (Bridel) Loeske

Plants dense, rigid, dark green to yellow-brown. Stems with branching angle wide, branches firmly attached; pseudoparaphyllia foliose; rhizoids below or at abaxial leaf insertion, red-brown, smooth. Leaves erect-spreading, 0.1-0.3 mm; base not much narrowed to insertion; margins entire or nearly so; alar cells subquadrate, region of 3-6+ cells; distal laminal cells oblong-rhombic, 2-3(-4):1. Specialized asexual reproduction absent. Sexual condition autoicous; perichaetial leaf margins entire or obscurely serrulate distally. Seta 0.6-0.8 cm. Capsule inclined to horizontal or rarely suberect, shortly oblong-cylindric, asymmetric, 0.8-1.2 mm, contracted below mouth when dry, neck short; stomata at base of capsule; annulus 2-seriate; operculum convex-conic, stoutly apiculate; exostome teeth yellow-brown; endostome cilia in groups of 2 or 3, well developed. Spores 11-13 µm.

Moist, shaded limestone rock, stream valleys; low to moderate elevations; Nfld. and Labr., N.S., Ont., Que., Yukon; Ala., Alaska, Ark., Conn., Ill., Ind., Iowa, Kans., Md., Mich., Minn., Mo., N.J., N.Y., Ohio, Pa., S.Dak., Tenn., Vt., Va., Wis.; Europe; w Asia.

Diagnostic features of Platydictya confervoides include entire or obscurely serrulate leaf margins and short laminal cells, as well as a rupestral habitat.