Culms 10-15 dm, rather soft, often decumbent and rooting from the lower nodes; main lvs 6-10 mm wide; ligule prominent; infl narrow, 2-4 dm, often somewhat spreading at anthesis; spikelets subsessile or short-pedicelled, 1-2 cm, 8-16-fld, the lemmas spreading at maturity; rachilla-joints 1.1-1.8 mm; glumes scarious, obscurely veined, elliptic to obovate, the first 1.9-3.9 mm, the second 2.8-5.1 mm; lemmas elliptic, 3.7-5.3 mm, dull and scaberulous between the veins, blunt or rounded and usually erose at the scarious tip; palea sometimes projecting as much as 1 mm; anthers 3, 1-1.7 mm; grain 1.5-2 mm; 2n=40. Shallow water or very wet soil; Mass. to Minn., s. to S.C. and Tex. (G. arkansana, a rare form with the lemmas minutely short-hairy instead of scabrous)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Infrequent to somewhat frequent in the lake area and local in the southern part of the state. It has the habitat of the preceding species [Glyceria borealis], growing only in very wet places or in shallow water.