Annuals, 3-15(-25) cm; taprooted or fibrous-rooted. Stems erect, usually branched from bases, sometimes simple, closely to loosely tomentose. Leaf blades oblanceolate, 1-5 cm × 1-3 mm. Bracts subtending heads linear, oblanceolate, or obovate, 5-15 × 1-2 mm, usually surpassing glomerules. Heads borne singly or in terminal, capitate glomerules, sometimes in axillary glomerules. Involucres 2-4 mm. Phyllaries brownish, bases woolly, inner narrowly triangular with whitish, acute apices. 2n = 14. Flowering Jul-Oct. Lake and pond margins, stream banks, wet meadows, other permanently or sporadically moist sites, disturbed sites; 1400-3000 m; Greenland; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Colo., Conn., Del., Idaho, Ill., Iowa, Kans., Ky., Maine, Md., Mass., Minn., Mont., N.H., N.J., N.Y., Ohio, Oreg., Pa., R.I., S.Dak., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe. Gnaphalium uliginosum is native to Europe; it is not clear whether some or all of the North American plants may have been introduced into the flora.