Answer. The grasslands mean a type of ecosystem that is covered with a large number of land covered with several kinds of grasses and which also includes small types of trees and shrubs. They are known for different names in the world. Prairie is one of them which is a type of temperate grasslands that are found in the interior of North America and got its origin from the Rocky Mountains. It formed almost 8,000 years ago and is spread among the areas of the United States of America, Canada, and Mexico. Its eastern part is full of moisture whereas the western part is much drier. It consists of short, mixed, and tall grasses here. Mostly, there are no trees but a few areas, trees can be found. It is a great source of flora and fauna as well.