Fraxinus quadrangulata

Stammborke of Blue Ash

The Blue Ash ( Fraxinus quadrangulata ) is a deciduous tree species from the genus of ash trees in the family Oleaceae. Their natural habitat is in the east of North America.


The Blue Ash is an up to 25 m high deciduous tree with rounded crown. The yellow-brown branches are sharp square, often winged and glabrous. The terminal buds are gray and broadly conical. The leaves are 20 to 30 inches long, composed and consist of seven to eleven short -stalked leaflets. The leaves are 6-10 cm long, narrowly ovate to lanceolate, often falcate curved, acuminate with wide wedge base. The leaf margin serrate with incurved teeth. The upper leaf surface is glabrous, the lower surface hairy along the midrib. The flowers are dioecious and are distributed in pendent panicles. Petals absent. The flowers appear before the leaves from April to May As fruits 2.5 to 5 centimeters long, flat, nut winged fruits are formed, the edge of wing runs down to the base.

Distribution and ecology

The distribution area of ​​Blue Ash extends from Ontario in Canada through the northeastern United States and Oklahoma up in the Southeastern United States. There she thrives as floodplain and riparian woodland or in dry forests on moderately dry to moderately moist, mildly acidic to strongly alkaline, sandy, gravelly or loamy, nutrient-rich soils in sunny locations. It is heat tolerant but only moderately frost hardy.


The Blue Ash ( Fraxinus quadrangulata ) is a species in the genus of ash (Fraxinus ) from the family Oleaceae ( Oleaceae ). It is assigned to the section Dipetalae.