Think of grass as a straw. This analogy is actually correct, because the first drinking straws were made of the hollow tubes of grass. Wheat and corn are grasses, as is bamboo. All of these plants are cousins of lawn grasses. Because of this, bamboo, corn, wheat and lawn grasses all have the same structure. Understanding this structure is important to understanding reproduction of the plant.
At the bottom of the straw, fibrous, thread-like roots draw in water and nutrients from the soil and anchor the plant to the ground. Above the roots, the straw-like grass stems attach to the roots at the crown. These stems are known as culms. They are hollow except around the joints where the stems attach to one another. These joints are known as nodes. A narrow leaf extends out from the stem just above each joint. The leaves alternate in direction. If the first leaf points to the left, the second will point to the right. The third leaf will then point to the left and so on. Grasses reproduce in one of two major ways: asexual and sexual reproduction.
Some grasses have stems that grow sideways along the ground. New grasses reproduce along these stems along nodes that touch the ground. This process is known as tillering. If the stems creep above the ground, they are known as stolons. Stems that crawl beneath the ground are known as rhizomes. The new plant is supported by the old plant until it can establish roots and support itself.
A second way that lawn grasses reproduce is through seeds. The grasses produce flowers singly or in groups. Single flowers are known as florets. Flowers that are produced in groups are known individually as spikelets and in clusters as inflorescences. These flowers cross pollinate each other through spores that are carried by the wind from one flower to the other. Some species of grass, such as the needle grass, can self-pollinate. Some species of bluegrass can produce a seed without pollination. These pollinated flowers produce seeds from which new plants will grow. The seeds are either dropped from the stalks or carried away by the wind. Depending on the species of grass, the seed may be dropped in the fall, or in the following spring.