Plants small. Stems freely branched. Leaves of stems and branches similar, 0.65--0.9 × 0.3--0.5 mm; proximal cells 9--24 ´ 11--21 µm, medial and distal cells 22--34 ´ 11--13 µm. Sexual condition autoicous. Seta 6--10 mm. Capsule 1.15--1.75 ´ 0.6--0.75 mm; exostome teeth triangular-lanceolate, 325--365 ´ 80--95 µm. Spores 14.5--19.5 µm, yellow.

Capsules mature May--Aug. Areas submerged at flood level, the bases of trees or shrubs, especially willows, edges of ponds or stream valleys; 0--1700 m; B.C., N.W.T., N.B., Ont.; Alaska; Europe; Asia (nw Siberia).

Myrinia pulvinata may be mistaken for a member of the genus Leskea because of similar habitat and leaf shape. Leskea species generally have a much stronger costa as well as papillose leaf cells. When sporophytes are present, Myrinia’s cross-striolate external exostome surface provides a distinction between the two genera. Myrinia pulvinata and Leskea polycarpa are often found growing intertwined.