Ammophila arenaria is a coarse, perennial grass with stout stems that may reach 120 cm tall with dense, spike-like panicles and long, sharp leaf blades which may reach up to 1.5m. It has extensive and deep, scaly rhizomes which may give it an advantage in accessing water and nutrients.

Ammophila arenaria grows in substrates with low organic matter and free drainage, growing most vigorously in mobile or semi-stable sand dunes and thriving in wind-blown, foredune areas above the high tide line.

Uses sun's energy for photosynthesis.

Ammophila arenaria primarily reproduces vegatatively both from rhizomes and small basal buds located at the base of stems under their lower leaf sheaths. It is capable of flowering from the end of June through August (in Oregon) but rarely produces viable seeds. Seedlings have been found in nature but occur rarely with any seedlings that are observed usually living no longer than seven weeks due to small-scale sand erosion, desiccation, or burial. However, at certain locations where water is retained by an impermeable layer of boulder clay and the soil remains damp for longer periods, seedlings may establish. Commonly known as marram grass, Ammophila arenaria is a beach grass native to Europe, the Mediterranean, and the coasts of the Black Sea. Widely distributed to stabilise and establish sand dunes for forestry plantings, property protection and erosion control, it can compete with and displace native vegetation communities and alter habitats with further consequences for invertebrate communities and bird species such as the endangered Chatham Island oystercatcher (Haematopus chathamensis). Once established, it spreads through rigorous rhizome growth and is difficult and costly to control.

http://www.issg.org/database/species/ecology.asp?si=1518&lang=EN accessed 13/02/14