Even in towns and cities, grasses are all around, providing a green carpet that softens the brick and concrete environment. In parks, gardens and sports grounds, the turfs may look the same, but each comprises a different mixture of grasses specially chosen to provide a suitable surface.
Elsewhere, grasses play other roles in the environment. Some help to mop up oil spills, some are suitable for stabilising mine spoilheaps or treating sewage, while others can reduce soil erosion.

A perfect pitch

Wimbledon’s Centre Court is planted with two cultivated forms of ryegrass (Lolium perenne). Three different types of ryegrass make up the rugby ground at Twickenham. In each case, the grasses have been specially bred to withstand the wear and tear of long arduous matches. Bowling greens, on the other hand, require a dense cover of fine-leaved grasses that don’t cause bowls to swerve as they roll. At one time, sea-washed turfs were lifted from salt marshes to provide the ‘green’. These consisted of specialised forms of red fescue (Festuca rubra). Today, most bowling greens consist of the non-creeping grass, Chewing’s fescue (Festuca rubra subspecies commutata), combined with brown top (Agrostis tenuis) to produce a thick smooth carpet.

As well as lawn grasses, gardeners also now grow different species as ornamentals in their borders. Particularly popular are Stipa gigantea with its tall golden sprays of seeds and Pennisetum villosum bearing softly furry seed heads.

Saving the soil

Rolling sand dunes rising up behind sandy beaches protect coastal areas against flooding and erosion, but are themselves fragile structures composed of shifting sand. With its dense mats of roots and creeping underground stems, marram grass (Ammophila arenaria) can stabilise existing dunes and trap sand blowing in from the beach. As the dunes become more permanent, other plants can colonise them and soil begins to build up.

Soil erosion is a particularly acute problem in tropical countries, where every rainstorm washes away fertile soil. Farmers plant rows of vetiver grass (Vetivaria zizanioides) to form protective barriers. With its dense tufts of leaves and deep rooting system, it retains soil and reduces water run-off.

Roots of vetiver grass contain a highly scented oil called vetiver or khus. This oil is an ingredient in several world-famous perfumes.