Plants: small or medium-sized, green or sometimes yellowish green to yellow. Stems: creeping, irregularly pinnate; paraphyllia sometimes present, 1-seriate, narrowly triangular or ovate. Stem: leaves spreading or ± squarrose, 1–2.3 × 0.4–1 mm; base erect to erect-spreading, cordate or rounded-triangular; acumen frequently differentiated, constituting 55–77% leaf length. Sexual: condition dioicous.
Mineral-rich wetland habitats, lowlands in swampy forests, open habitats at higher elevations, lake and stream shores. low to high elevations. Greenland, Alta., B.C., Nfld. and Labr. (Labr.), N.W.T., N.S., Ont., Que., Yukon, Alaska, Colo., Idaho, Ill., Ind., Maine, Mass., Mich., Minn., Mont., Utah, Wash., Wis., Wyo., Eurasia. Discussion.