The mosses constitute a large group of approximately 9,500 species of small plants.
Mosses are often abundant in moist areas, world wide.
In these moist areas, mosses often dominate the entire area. A large number can withstand long periods of very cold temperatures, such as are found in Antarctica. Many moss species can withstand dry climates, such as are found in the deserts. In these dry areas, some mosses form large masses in dry, exposed rocks where it becomes very hot. Many mosses have adapted so that they can live for several years in a dry condition without water.