This is perhaps the most familiar plant of British dunes: Marram grass, Ammophila arenaria. It's extensive rhizomes stabilise the sand preventing drifting of the dunes. The plant was harvested in the past for various uses, including thatching and basket-making, but this led to dune movement and loss of arable land and villages, especially in Denmark. Laws were introduced in Scotland in the seventeenth century and Denmark in the eighteenth century to prevent its removal.
The genus name derives from the Greek ammos: sand, and philia: lover. It is an example of a xerophyte, able to tolerate drought through various adaptations that help reduce water loss: waxy covering; inrolled leaves with stomata on the internal surface only; stomata situated in small pits; hairs to slow air movement across the leaf surface.