Plants: 3–7 cm. Stem: leaves stiff when dry or moist, 1.5–2 mm; margins serrulate distally; apex acute to short-acuminate; costa narrow, ending before apex. Sexual: condition dioicous. Seta: 2.5–4.5 cm. Capsule: 2–3 mm. Spores: 15–22 µm.
Calcareous wet fens. low to high elevations. Greenland, Alta., B.C., Man., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon, Alaska, Colo., Iowa, Maine, Mich., Minn., Mont., N.Y., Vt., n Eurasia.
Paludella squarrosa is one of the most spectacular moss species in the flora area. The squarrose-recurved leaves (more squarrose than in any other species, including Rhytidiadelphus squarrosus), combined with the calcareous wet fen habitat are all that is needed for identification.