Puccinellia laurentiana is a perennial grass which grows on gravelly seashores in south-eastern Canada.

Puccinellia laurentiana has solitary or somewhat tufted culms growing 10–30 cm (3.9–11.8 in) high.

The acute glumes are erose to serrulate; the first glume is 1–2 mm (0.039–0.079 in) long, narrowly ovate and acutish, with one nerve, and the second is 2–2.5 millimetres (0.079–0.098 in) long, broadly ovate and abruptly acute, with three nerves.

The ovate lemmas are 2.3–2.8 mm (0.091–0.110 in) long and profusely pubescent on their lower nerves.

[2] Puccinellia laurentiana grows on gravelly seashores and sea cliffs in south-eastern Quebec and north-eastern New Brunswick, often on the Gulf of St. Lawrence for which it is named.