Ash (Fraxinus), genus of trees or shrubs of olive family (Oleaceae). About 60 species occur worldwide, primarily in cold temperate regions; 4 are native to Canada. Native ashes (white, red, blue and black) grow in the East; some forms of red ash reach southeastern Alberta. Trees are of medium height with generally straight, slender trunks. The large compound leaves, consisting of 5-11 leaflets, occur in pairs on the twig. The small, dark flowers are grouped in clusters.

Ashes produce large amounts of fruit in the form of winged seeds, which remain on the tree well into winter and are an important food source for birds and squirrels. Ashes prefer the rich, moist soils of swamps and riverways. Except in black ash, the wood is heavy, hard, tough and strong and widely used for sporting goods, tool handles and furniture.

See Aboriginal Uses of Plants.