Grass plants have underground stems. These may be up to nearly two metres in length. Fibrous roots grow from these stems. The underground stems and roots grow together to form a mat. This forms a hard-wearing material which holds the soil in place. Leaves grow upwards from the stems. The point at which growth takes place is at ground level. When grazing animals feed, their mouths cannot reach the growing point and so, although most of the leaf is eaten, the part which makes new leaf survives.

The grass plant produces leaves as if they were on a conveyor belt for the grazing animals to eat.

When the grass plant breeds it produces a flower stalk. The flowers are small and green. They are wind pollinated. Each flower releases its pollen first then collects pollen from other flowers. Each flower forms a seed which we usually call a grain.

Grain is a cultivated form of grass whose seeds we use as food.