Plants robust, soft and sleek, 3--5 mm wide measured across leafy stem, to 15 cm long. Stems remotely and irregularly branched to subpinnately branched; branches commonly to 40 mm, decreasing rather regularly in length distally on the stem. Stem leaves erect-spreading, often falcate-secund or recurved distally, ovate-lanceolate, plicate, not rugose, 3.2--4.2 × 0.9--1.4 mm; base loosely sheathing, not rounded to the insertion; apex rather abruptly narrowed to a long, slender, channeled acumen; costa extending less than 1/4 leaf; median cells 40--80 × 5--7 µm, smooth; alar cells not differentiated from basal cells. Branch leaves narrowly lanceolate, base not sheathing, 1.7--3.6 × 0.4--1.0 mm. Capsule ovoid, 1.3--2.5 mm.

Especially common on logs, but also covering soil, humus, rock, and even tree bases, floor of moist coniferous forests, abundant near the coast, but rare elsewhere; 0--1000 m; St. Pierre and Miquelon; B.C., Nfld., N.S., Que.; Alaska, Calif., Idaho, Mass., Mont., Oreg., Wash.; Europe; Atlantic Islands.

A specimen of Rhytidiadelphus loreus from Owen Sound, Ontario (Moxley, July 1925, DUKE) is correctly determined, but the locality is very doubtful. In Quebec R. loreus is known only from Îles de la Madeleine in the Gulf of St. Lawrence.