Grass

Grass is a type of plant with narrow leaves growing from the base. Their appearance as a common plant was in the mid-Cretaceous period. There are 12,000 species now.

A common kind of grass is used to cover the ground in places such as lawns and parks. Grass is usually the color green. That is because they are wind-pollinated rather than insect-pollinated, so they do not have to attract insects. Green is the best colour for photosynthesis.

Grasslands such as savannah and prairie are where grasses are dominant. They cover 40.5% of the land area of the Earth, but not Greenland and Antarctica.

Grasses are monocotyledon herbaceous plants. They include the "grass" of the family Poaceae, which are called grass by ordinary people. This family is also called the Gramineae and includes some of the sedges (Cyperaceae) and the rushes (Juncaceae). These three families are not very closely related, though all of them belong to clades in the order Poales.