III.

Distribution and Size Range

Grasses are the most widely distributed group of flowering plants, occurring from well above the Arctic Circle through the temperate and tropical regions to Antarctica. Indeed, grasses are the only flowering plants to grow on the Antarctic continent. This huge geographical range is paralleled by great ecological amplitude and variation in size. Grasses are most abundant in open habitats such as prairies, tundra, steppes, savannas, and paramos (see Grassland), but many species occur in forests, particularly in the Tropics. Some are adapted to aquatic habitats, including salt water, fresh water, and still or running water. A few species float on the water’s surface and are not attached to the ground. Grasses also occur in desert regions.

In size, grass plants range from tropical giant bamboos that reach a height of more than 100 m (more than 330 ft) to annual bluegrass, only a few centimeters tall. Some grasses lack leaf blades, but the blades of others may attain a length of 5 m (16 ft).