Swamp Ecosystem-Black Ash

Black Ash

Order: Lamiales

Family: Oleaceae

Genus: Fraxinus

Species: F. nigra

General Characteristics: Fraxinus nigra is largely restricted to swamps. The sessile leaflets (no stalks) are characteristic and the tips of the leaflets tend to droop. If branches have good annual growth in length, the last pair of lateral buds tend to be clearly separated from the terminal bud. The bark of trees over about 3 inches in diameter is also often distinctive, although difficult to describe.

Special Adaptations: Black ash typically grows in bogs, along streams, or in poorly drained areas that often are seasonally flooded. It is most common on peat and muck soils but also grows on fine sands underlain by sandy till or on sands and loams underlain by lake-washed clayey till. Although this species can tolerate semistagnant conditions, for best growth it is important that the water be moving so the soil will be aerated even though saturated. Soils suitable for black ash are common in Canada and the northern States. In Indiana, such soils are most common in glaciated areas and in the White River Valley, but in Pennsylvania, they most frequently occur south of the glaciated areas. These soils are most commonly found in the orders Histosols and Entisols. Black ash is tolerant of a wide range of pH conditions, from 4.4 to 8.2.