Ammophila (plant)

Ammophila is a genus of flowering plants that includes two or three very similar species of grasses. The name Ammophila comes from Greek words meaning "sand" and "friend", which makes sense because these grasses grow almost exclusively on coastal dunes. They are commonly called marram grass, bent grass, or beachgrass.

These grasses have a special system of underground stems called rhizomes that help them survive in places with shifting sands and strong winds. This system also helps stabilize the dunes and prevent coastal erosion. Ammophila grasses are native to the coasts of the North Atlantic Ocean, especially around the Great Lakes in North America.

Although they grow near the sea, these grasses are not very tolerant of salty soils, but they can handle a moderate amount of salt. Because they are good at building and stabilizing dunes, people have introduced them to many places far from their native homes. However, in many of these new locations, Ammophila has become invasive, meaning it grows too well and harms local plants and animals. Efforts to control these invasive grasses include using special treatments and mechanical methods to remove them.

Species

There are two main species of Ammophila grasses: A. arenaria and A. breviligulata.

• European marram grass or European beachgrass grows along the coasts of Europe, including Iceland, and parts of northwest Africa.
• American marram grass or American beachgrass is found along the coasts of eastern North America, including the shores of the Great Lakes.

Some scientists have suggested two more species, but they are not fully confirmed. One, called Purple marram, is a mix between A. arenaria and Calamagrostis epigejos, found in parts of northern Europe near the Baltic Sea. Another, Champlain beachgrass, is very similar to A. breviligulata and grows around Lake Ontario and Lake Champlain.

Ecology

In Europe, Ammophila arenaria grows mainly along coastlines and is the most common plant on dunes. It helps build up dunes by catching blown sand and holding it in place with its strong, tough roots. This grass is especially important in areas where the sand is still moving.

Marram grass is closely linked with two types of coastal plants found in the British National Vegetation Classification. In areas with lots of moving sand, Ammophila is the main plant. In places where there is less sand moving, other plants like Festuca rubra (red fescue) become more common.

Uses

Marram grass is very useful because it can grow in sandy places and help keep the sand in one spot. This makes it great for keeping coastal dunes and sandy shores stable. People have known about this since the late 1700s.

In places like the North Sea coast of Jutland, Denmark, people used marram grass for fuel, making roofs, and feeding animals after frost. However, using the grass sometimes caused sand to move and cover farmland. To stop this, laws were made in 1779 and 1792 to help protect the dunes.

In Newborough, Wales, women used marram grass to make mats, covers for haystacks, and brushes. The grass has also been used for making roofs in many seaside areas of the British Isles. In the 1600s, taking marram grass for roofs caused problems because it made dunes unstable, covering villages and farms. In 1695, Scotland made a law to stop people from taking the grass from sand hills.

Adaptations

Marram grass is specially designed to survive in dry and sandy places where water is scarce. It has special leaves that roll up to trap tiny bits of water vapor, helping the plant keep its moisture. The tiny openings on the leaves, called stomata, are hidden in little pits, which stops them from opening too wide and losing water. Inside the rolled leaves, there are also hairs that slow down the wind, further helping the plant hold onto its water. Additionally, a waxy coating on the leaves works like a shield to prevent water from evaporating into the air.