Tussock grass is a type of grass that does not form lawns but instead grows in clumps or tufts. Tussock grasses, sometimes called bunch grasses in North America, belong to the Poaceae plant family and are perennials. They vary greatly in appearance: some species grow up to 7 feet (2 m) tall, and others are only a couple of inches (about 5 cm) high. Many species of tussock grass are hardy and can thrive even in poor soil and under dry or otherwise difficult conditions, which is one reason that they can be found in almost every part of the world, in many different types of climate zones and habitats — the tropics, wetlands, alpine areas, tundra, deserts, riverbeds, grasslands, forests and beaches. Various species are native to Africa, Asia, Europe, North America, South America, Australia and New Zealand.
Some tussock grasses, such as blue fescue, are used as garden plants. They are valued for their hardiness and drought-tolerance and for their extensive root systems that can help control soil erosion. Other species of tussock grass, such as June grass, are even used as a low-maintenance ground cover, such as on the roughs of golf courses, but although it is hardy, it does not tolerate high-traffic use.
In some areas, most commonly found in the temperate regions of the southern hemisphere, tussock grass is the dominating form of plant life. Such tussock grasslands can be found in New Zealand, southern and eastern Africa as well as Argentina and Australia. New Zealand is home to many unique species of tussock grass. One of these is called snow grass. Apart from being hardy, this tussock grass is known both for being extremely slow-growing and for its longevity, and some of the individual plants are many hundreds of years old.
The Poaceae family, to which tussock grass belongs, is sometimes referred to as "true grasses." The true grasses share some defining characteristics. Among the most important: they are flowering plants that have only one embryo leaf; they have hollow stems with nodes from which the leaves grow; they have small flowers that don't have petals, that are grouped together into a spike and that are pollinated by the wind rather than insects; and instead of fruit, they bear grain that is essentially seed and fruit combined into one.
Grasses are of great importance to human beings. Major food crops such as rice, wheat, sugar cane and corn are all different kinds of grasses. Other types of grasses, including many species of tussock grass, are valuable to humans as nutritious forage for livestock. Tussock grasses, and grasses in general, also are important as food sources and habitats for wild animals, birds and insects.