Lyme grass is similar to marram grass in appearance however, they have large, spiked flowerheads with unstalked heads in opposite, alternating pairs running up their stems. Lyme grass has broad, grey-green leaves with sharp pointed tips.

Like marram grass, lyme grass is a psammophilic (sand-loving) species and can be found around the coast of Ireland, mainly within sand dunes and occasionally on fine shingle. Lyme grass is most common on eastern and northern coasts in Ireland.

Lyme grass is a native perennial plant to Ireland. It flowers between July and August.

In Europe, the plant’s stems are used for roof thatching and can be woven into a coarse fabric. Seeds have provided food in the past. Beginning as early as the 18th century, the plant’s extensive network of roots was used in stabilising sands on northern coastal beaches.