Grasses

Grasses appeared in the middle of the Mesozoic era. Woody plants appeared earlier than did herbaceous plants. Woody is primitive, and herbaceous derived from woody ancestors. While most plants have their meristematic cells at the tips, grasses have their dividing cells near the nodes. This is a splendid development because it makes possible continued growth after grazing or cutting. We owe our very lives to this singular characteristic of grasses. There are approximately 5,000 species of grass. Blue grass, bent grass, timothy, fescue, crab grass, and quack grass are all grasses as are the grain cereals, wheat, rice, oats, barley, corn, sugar cane, sorghum, millet, and bamboo. There are vastly more species of extinct forms of grass than there are of living forms. It is postulated that nine-tenths of all species that have ever lived are extinct. Extinction, then, is more common than is survival-for both plant and animal forms.<