Plants annual; tufted. Culms 9-70 cm, clustered or solitary. Sheaths smooth, glabrous; ligules 2.5-5(10) mm, obtuse, entire; blades 3-13.5(23) cm long, 2.5-14 mm wide, scab¬rous. Panicles 1-4(8) cm long, 0.7-2 cm wide, ovoid to almost globose, unilateral. Spikelets 7-14 mm, subsessile or shortly pedicellate; pedicels to 1.6 mm. Sterile spikelets with 6-18 florets; glumes and lemmas similar, subulate to linear-lanceolate, glabrous, sometimes scabridulous, awned, awns to 8 mm. Fertile spikelets with 1-5 florets, glumes and lemmas dissimilar; glumes 5.5-12 mm long, 0.4-0.9 mm wide, narrowly lanceolate, laterally compressed, hyaline, glabrous, 1-veined, keeled, awned, awns 0.5-2.2 mm; rachilla internodes 0.9-1.3 mm; lemmas 4-7 mm, slightly dorsally compressed, chartaceous or coriaceous, not keeled, lower 1/2 smooth, glabrous, distal 1/2 villous or scabrous, apices hyaline, ciliolate, entire or bidentate, awned, awns 5-18(25) mm; anthers 1-4 mm. 2n = 14.
Wash., B.C., W.Va., N.J., N.Mex., Tex., La., N.C., S.C., Tenn., N.Y., Pa., Va., Calif., Ala., Ark., Ga., Conn., Md., Okla., Ohio, Mo., Mich., Mont., Miss., Oreg.
Cynosurus echinatus is native to southern Europe. It is now established in dry, open habitats in North America, South America, and Australia.