Plants perennial; cespitose, often stoloniferous, not mat-forming. Culms 20–100 cm, erect to decumbent. Ligules 1–3.5 mm, obtuse to truncate, entire; blades 2–4.4 mm wide, flat to involute. Panicles 3–30 cm, compact to diffuse at maturity, lower branches erect to descending, spikelet-bearing from about midlength; pedicels usually densely scabrous, occasionally with only a few scattered scabrules, often with tumid epidermal cells. Spikelets 5.5–13 mm, with 4–9 florets. Glumes rounded over the back, veins obscure, apices acute to obtuse; lower glumes 2–3.4 mm; upper glumes 3–4.5 mm; calluses with few to many hairs; lemmas 3–5 mm, slightly to markedly coriaceous throughout, sparsely to densely hairy in the lower 1/2, principally along the veins, backs rounded, 5-veined, veins obscure, usually not extending to the margins, sometimes the midvein doing so, apical margins usually smooth, sometimes with a few scattered scabrules, occasionally densely scabrous, apices acute to obtuse, entire; palea veins ciliate proximally, scabrous to short-ciliate distally; anthers 1.5–2.6 mm. 2n = 14–77, usually 56.
Puccinellia maritima grows in coastal environments in North America and Greenland. It is native to Europe; most or all occurrences in the Flora region are probably the result of human introduction.