Black ash

Leaves

Form

• Pinnately compound
• 7–11 leaflets
• Leaflets elongated, oval, stalkless
• Bases unequally rounded or broadly wedge-shaped
• Tapered to a long, slender tip
• Hairless except for dense tufts of hairs where leaflets attach to leaf stalk
• Whole leaves rather than leaflets tend to fall in autumn

Length

• Leaflets 10–14 cm
• Leaflets and central stalk 15–30 cm

Colour

• Both surfaces dark green
• Hairs reddish-brown

Autumn colour

• Reddish-brown

Margin

• Finely and sharply toothed

Buds

Form

• Terminal bud present, broad, pointed
• Uppermost pair of lateral buds set distinctly below the terminal bud
• Bark clearly visible above them
• Leaf scars large, rounded

Length

• Terminal bud 4–10 mm

Colour

• Dark brown

Twigs

Form

• Very stout
• Raised lenticels when young

Colour

• Bright green with dark purple becoming dull grey

Flowers

Form

• Panicles
• Flower clusters more likely to occur at the twig tip than in other ash species

Structure

• Polygamo-dioecious

Floral timing

• Before the leaves

Fruits

Form

• Wing broad, often twisted
• Sometimes slightly notched at the tip
• Extending to base of flattened seedcase  

Length

• 2.5–4 cm

Structure

• Samara

Bark

Form

• Soft, with corky ridges that are easily rubbed off by hand
• Becoming scaly 

Colour

• Light grey

Wood

Morphology

• Straight-grained, flexible

Uses

• Snowshoe frames, barrel hoops, canoe ribs, woven basketware

Size

Height

• To 20 m 

Diameter

• To 50 cm

Tree form

Forest-grown

Trunk

• Slender
• Sometimes bent or leaning

Crown

• Narrow, open
• Coarse, ascending branches

Root system

• Shallow
• Wide-spreading

Habitat

Site

• Common in northern swampy woodlands
• Tolerates standing water for many weeks

Light tolerance

• Intolerant of shade

Associated species

• Sometimes in pure stands
• Usually mixed with black spruce, balsam fir, eastern white-cedar, speckled alder, red maple, and silver maple

Range

Eastern Manitoba to the Atlantic provinces