Plants annual or biennial. Stems erect, simple or branched, 4-88 cm, often pubescent. Leaves: sheath 1-4 mm, 1-2 times as long as stem diam.; blade linear to narrowly oblanceolate, 2-10.5 cm, green, margins basally ciliate. Inflorescences usually open 3-6-flowered cymes or flowers some-times solitary; bracts linear, equaling or longer than calyx, herbaceous, apex acute; bracteoles 4, green, linear to lanceolate, 4-1 times as long as calyx, herbaceous, apex acute. Pedicels 0.1-3 mm. Flowers subsessile; calyx 20-25-veined, 11-20 mm, pubescent, lobes acuminate, 2-7 mm; petals reddish with white dots (rarely all white), bearded, 3-8(-10) mm, apex dentate. Capsules 10-16 mm, slightly shorter than calyx. Seeds 1.1-1.4 mm. 2n = 30 (Europe).

Flowering spring and summer. Roadsides, fields, shores, open woods, waste places; 0-2300 m; introduced; Alta., B.C., N.B., N.S., Ont., P.E.I., Que.; Ala., Ariz., Ark., Calif., Colo., Conn., Del., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; w Asia; introduced in South America (Chile), Pacific Islands (Hawaii).

Subspecies armeria is occasionally cultivated, as in Louisiana, where apparently it has not yet escaped. It was collected at Stephenville, Newfoundland, in 1972 (Rouleau 11293, CAN, MT), but apparently has not become established there.