Culms 20-100 cm, erect, or decumbent and rooting at the nodes. Blades (2) 5-8 (26) cm long, 4-10 mm wide, folded, apices obtuse. Panicles with (1) 4-6 (11) branches; branches 2-11.5 cm. Spikelets 1.5-2.1 mm; florets 2-3. Lower glumes 1-1.7 mm, apices acute; upper glumes 1.5-1.8 mm, obovate, bilobed, lobes acute or obtuse, awned from between the lobes, awns 0.3-0.9 mm; calluses glabrous or with a few hairs, hairs to 0.3 mm; lowest lemmas 1.5-2 mm, ovate, dark-brown at maturity, lateral-veins and keels with appressed, brown hairs, hairs to 0.4 mm, apices mucronate; second lemmas about 1 mm, broadly cuneate, occasionally mucronate, apices rounded or truncate. Caryopses 1-1.2 mm. 2n = 40.
Pa., Ga., Tex., La., Puerto Rico, Virgin Islands, Ala., N.C., S.C., Pacific Islands (Hawaii), Miss., Fla.
Eustachys petraea grows on dunes and open sandy areas and along roadsides and salt and brackish marshes. Its range extends south from the United States through Mexico to Panama.
"decumbent" is not a number.