Ammophila arenaria is a species of flowering plant in the grass family Poaceae. It is known by the common names marram grass and European beachgrass. It is one of two species of the genus Ammophila. It is native to the coastlines of Europe and North Africa where it grows in the sands of beach dunes. It is a perennial grass forming stiff, hardy clumps of erect stems up to 1.2 metres (3.9 ft) in height. It grows from a network of thick rhizomes which give it a sturdy anchor in its sand substrate and allow it to spread upward as sand accumulates. These rhizomes can grow laterally by 2 metres (7 feet) in six months. One clump can produce 100 new shoots annually.
The rhizomes tolerate submersion in sea water and can break off and float in the currents to establish the grass at new sites. The leaves are up to 1 metre (3.3 ft) long and sharply pointed. The cylindrical inflorescence is up to 30 centimetres (12 in) long. It is adapted to habitat made up of shifting, accreting sand layers, as well as that composed of stabilised dunes.
Invasiveness: Pacific coast of North America
A. arenaria is also recognised[by whom?] as one of the most problematic noxious weeds of coastal California. This sand-adapted grass was introduced to the beaches of western North America during the mid-19th century to provide stabilization to shifting sand dunes. It grew readily and it can now be found from California to British Columbia. The grass is invasive in the local ecosystems, forming dense monotypic stands that crowd out native vegetation, reduce species diversity of native arthropods, and cover vital open stretches of sand used for nesting by the threatened western snowy plover (Charadrius nivosus). The plant's spread has changed the topography of some California beach ecosystems, especially in sand dunes. The presence of this grass was a major cause of the destruction of native dune habitat in Oregon and Washington during the 20th century,  where it was planted precisely for its dune-stabilizing effect. 
Several methods have been employed in attempts to eradicate the grass in California, including manual pulling, burning, mechanical removal followed by salt water irrigation, and glyphosate application. Studies to find the best methods are ongoing.
Not only is it invasive in California, it is also a highly invasive weed in coastal areas of New Zealand and Western Australia, where it was introduced for the same purpose in California to stabilise dunes; outcompeting native spinifex species.
Ammophila arenaria is a perennial plant, which can live for many years. It mainly grows in spring and leaf production exceeds lead senescence. But the condition in autumn is contrast that it nearly stop growth while its leaves become senescence. In winter, since the temperature is so cold, the growth is very slow but rather than stopping growth.
This plant is highly adaptive in sand, which can withstand burial for more than one year. Unlike the other plant which will die in sand, this plant will elongate its leaves when it buries by sand.
Its inflorescences are initiated in autumn of the second year after germination and mature in May or June, and its flowers are always produced from May to August. But this is changed to May in Europe because of the different climates. And it is always mature in September, and the seeds germinate in the next spring. Though the plant is strong in live, it has a low viability for seeds, and the seeds are in low survival ability too because of desiccation, burial and erosion. The main organ for its production is rhizomes, which is dispersed along the shore by wind and water.
Geographic distribution and habitat
Natural global range
Ammophila arenaria is a European and North African native plant. It occurs in Australia, Canada, Chile, Falkland Islands (Malvinas) (sub-Antarctic), New Zealand, South Africa and United States (USA).
New Zealand range
Usually occurs on sand dunes, sometimes in inland sites with low fertility. It occurs in the Wellington region and extends from to 55 to 32 degrees south latitude. In the Northern Hemisphere, it grows between 30 and 63 degrees north latitude. Occurs in Chatham Islands, Otago Region, Doughboy Bay and Mason Bay.
Ammophila arenaria grows in sediment low in organic matter and with good drainage, mostly on mobile or semi-stable sand dunes. It is highly suited for sandy habitats and grows fast, avoiding senescence with continuous supply of fresh sand. The soil range suit for the Ammophila arenaria grows from 4.5 - 9.0 and the temperature range from 10 - 40 degrees, and salt concentrations of no more than 1 - 1.5%. In inland situation, other species establish habitat when the sand is stable and Ammophila arenaria displaces other native plants along the coast.
Diet and foraging
Marram grass plants on coastal sand dunes all over the world. It more like growing on the active sand area and windward side of foredune. It should be planted on well-drained soils with different kinds of mineral compositions. The best soil condition for marram grass is the soil pH range from 4.5-9.0, soil temperature from 10-40 degrees Celsius. Marram grass can be found on a high alkaline which pH around 9.1 and also found on acid lands which pH less than 4.5. Adult plants tolerate has a large range of chemical issues. Marram grass has a well ability to adapt dry sand. Leaves rolled and tight when the moisture levels are low.
Predators, parasites, and diseases
Marram grass do not record serious main disease in New Zealand, because only 3 pathogenic fungi (Claviceps purpurea, Uredo sp. and colletotrichum graminicola) are present on the island. These three fungi result in ergot, rust and leaf spot and are found both on flower-heads and leaves. However, in European countries, there are a lot of pests known to feed on marram grass. Those pests killed 30%-40% of the tillers, and also damaged other species. Those fungi, always found in soil, may decrease the vigour on the stabilized sand.
Marram grass can be useful for edible uses, medical uses and other uses. People use the flowering stems and leaves for thatching, basketry and making brooms. Fiber from the stem is used for making paper, then the rhizomes are used for making rope and mats.
- Apteker, Rachel. "Invasive Plants of California's Wildland: Ammophila arenaria". California Invasive Plants Council. Retrieved 2008-09-18.
- "UC Cooperative Extension Species Profile: Ammophila arenaria". University of California. Retrieved 2008-09-18.
- Pickart, Andrea J. (1997). "Control of European Beachgrass (Ammophila arenaria) on the West Coast of the United States" (PDF). 1997 Symposium of the California Exotic Pest Plant Council. Retrieved 2008-09-20.
- Encyclopedia of Life, 2015, Ammophila arenaria.
- Huiskes, A. H. L. (1979). Ammophila arenaria (L.) Link (Psamma arenaria (L.) Roem. et Schult.; Calamgrostis arenaria (L.) Roth). The Journal of Ecology, 363-382.
- Ranwell, D. (1960). Newborough Warren, Anglesey: II. Plant associes and succession cycles of the sand dune and dune slack vegetation. The Journal of Ecology, 117-141.
- Russo, M., Pickart, A., Morse, L., & Young, R. (1988). ELEMENT STEWARDSHIP ABSTRACT for Ammophila arenaria.
- Wallén, B. (1980). Changes in structure and function of Ammophila during primary succession. Oikos, 227-238
- "Ammophila arenaria". Global Invasive Species Database. Retrieved 4 May 2015.
- "Ammophila arenaria". New Zealand Plant Conservation Network. Retrieved 4 May 2015.
- Gadgil, R.L. (2006). "Marram Grass-Friend or Foe?". A Review of the Use of Ammophila Arenaria on New Zealand Sand Dunes. Coastal Dune Vegetation Network Technical Bulletin No. 5.
- Ranwell, D. (1960). "Newborough Warren, Anglesey II". The Journal of Ecology: 117–141.
- Pickart, Andrea J (1997). Control of European Beachgrass (Ammophila arenaria) on the West Coast of the United States. . The Nature Conservancy Lanphere-Christensen Dunes Preserve Arcata. p. CA 95521.
- Ranwell, D. (1959). Newborough Warren, Anglesey. I. The dune system and dune slack habitat. J. Ecology. 47(3), pp.571-601
- Gadgil, R. L. (2006). Marram Grass – Friend or Foe? A Review of the Use of Ammophila arenaria on New Zealand Sand Dunes. First Published by New Zealand Forest Research Institute Limited, Rototua.
- Gadgil, R. L. (2002). Marram Grass (Ammophila arenaria) and Coastal Sand Stability in New Zealand. New Zealand Journal of Forestry Science. 32(2), pp.165-180.
- Plant For A Future. (n.d.). Ammophila arenaria - (L.)Link. Retrieved from http://www.pfaf.org/user/Plant.aspx?LatinName=Ammophila+arenaria
|Wikimedia Commons has media related to Ammophila arenaria.|
- Ammophila arenaria - U.C. Photo gallery
- Jepson Manual Treatment - Ammophila arenaria (invasive species)
- USDA Plants Profile
- New Zealand website: Plant details - Marram grass - discussing control of Ammophila arenaria.