Ammophila (Poaceae)

Ammophila (synonymous with Psamma P. Beauv.) is a genus consisting of two or three very similar species of grasses; common names for these grasses include Marram Grass, Bent Grass, and beachgrass. These grasses are found almost exclusively on the first line of coastal sand dunes; their extensive systems of creeping underground stems or rhizomes allow them to thrive under conditions of shifting sands and high winds, and to help stabilize and prevent coastal erosion. Ammophila species are native to the coasts of the North Atlantic Ocean where they are usually the dominant species on sand dunes. Their native range includes few inland regions, with the Great Lakes of North America being the main exception. The genus name Ammophila originates from the Greek words ἄμμος (ámmos), meaning "sand", and ϕιλος (phillia), meaning "lover".

The Ammophila grasses are widely known as examples of xerophytes, which are plants that can withstand windy conditions such as north pole. Its xerophytic adaptations (mentioned below) allow it to thrive under conditions most plants could not survive. Despite their occurrence on seacoasts, Ammophila grasses are not particularly tolerant of saline soils; they can tolerate a salinity of about 15 g/l (1.5%), which makes them "moderate halophytes".