Plants golden green to yellow-green to pale green, glossy, soft, large to small, 1--5 cm, varying from irregularly branched to few branched to somewhat pinnately branched, branches 0.2--2 cm. Stems reddish brown to yellowish green, brown with age, epidermal cells conspicuously hyalodermous, central strand well developed, suberect to prostrate; rhizoids usually rare to absent; pseudoparaphllia foliose. Leaves falcate-secund (sometimes weakly so), oblong-ovate, tapering gradually to a slender or broad acumen, 0.5--2 mm × 0.5--1 mm, decurrent, not or slightly rounded to insertion, margin entire to blunt serrate especially in acumen, plane; costa short and double; median cells linear 60--100 × 5--6 µm wide, basal cells yellowish, porose, wider and shorter; alar cells in a decurrent group of well-defined marginal group, usually swollen and thin walled, in 2--4 rows, delimited by 1--3 rows of shorter cells distally. Sexual condition dioicous; inner perichaectial leaves erect, oblong-lanceolate, deeply plicate, attenuate, margins serrulate at tip, costa obscure. Seta reddish brown, 2.5--4 cm, capsule pale brown, inclined, cylindric, curved, 2--3 mm, excluding conic-convex operculum; furrowed when dry; annulus 2--3 seriate; cilia of endostome 2--4, as long as segments.

Producing sporophytes infrequently spring--summer; capsules maturing June--Aug. Terrestrial, commonly in open sites, wet soil, humus, logs, sand of lake and river margins, swamp forests; 0--3000 m; Greenland; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Maine., Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I. S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; Asia.

Hypnum lindbergii is largely a species of temperate climates, most frequent in boreal and warm temperate regions, less frequent in the Arctic, occurring from sea level to alpine elevations. In North America: The hyalodermous cortical cells, leaves usually curved to insertion, usually well-defined alar regions of swollen thin-walled cells, and often wide acute apex of many stem leaves usually separate this species from similar taxa. Hypnum pratense resembles it somewhat, but tends to be very glossy, the stem leaves often complanate, and thin-walled alar cells are lacking. With further study, H. lindbergii var. americanum (Renauld & Cardot) Whitehouse may prove to be worthy of recognition.