Beech (Fagus), genus of trees of beech family (Fagaceae). Ten species occur worldwide; one, American beech (F. grandifolia), is native to North America. In Canada, this species is found primarily in the East.

American beech has a straight trunk covered with thick, smooth, bluish grey bark and can attain 30 m in height. The leaves are alternate, single, long ovals with saw-toothed edges. Leaves of young trees often remain on the twigs throughout winter. The edible beechnut is an important food source for a number of animals, particularly squirrels.

American beech is usually found with sugar maples on temperate, well-drained slopes. Its leaves decompose very slowly, forming a thick leaf litter which acidifies soil and makes regeneration of sugar maple increasingly difficult.

European beech (F. sylvatica) is planted as an ornamental in Canada. Varieties include copper beech, weeping forms, variegated leaf forms. The heavy, hard, tough wood is used for tool handles, floor planks and furniture.