Trembling aspen

Leaves

Form

• Broadly oval to kidney-shaped
• Tip abrupt, short, sharp
• Base rounded
• Usually hairless
• Preformed leaves usually broadly oval
• Neoformed leaves heart-shaped, often larger or smaller than preformed leaves and with more readily visible basal glands

Length

• 3–7 cm

Colour

• Upper surface deep green
• Lower surface paler

Margin

• Teeth fine, irregular (20–30 per side)
• Teeth more numerous in neoformed leaves

Petiole

• Flattened
• Slender
• Usually longer than the blade
• Round in neoformed leaves

Timing

• 7–10 days earlier than largetooth aspen

Buds

Form

• Flower buds larger
• Leaf buds smaller
• Conical, pointed, appressed, with the tips curving inward
• 6–7 scales, shiny, slightly resinous, not fragrant
• Leaf scars small, triangular

Length

• 6–7 mm

Colour

• Dark reddish-brown

Twigs

Form

• Slender, shiny, round in cross-section
• Lenticels oval

Colour

• Dark green or brownish-grey

Flowers

Structure

• Dioecious

Fruits

Form

• Stalk hairy
• Capsules narrowly conical, hairless
• Splitting into 2 parts when mature
• About 10 seeds

Length

• Mature seed catkins 10 cm
• Capsules 5–7 mm

Timing

• Seeds ripen 4–6 weeks after flowering

Bark

Form

• Smooth with a waxy appearance
• Becoming furrowed into long flat-topped ridges
• Diamond-shaped marks about 1 cm across sometimes occur

Colour

• Pale green to almost white when young, becoming darker

Wood

Uses

• Manufacture of oriented strand board and other forms of chipboard

Size

Height

• To 25 m

Diameter

• To 40 cm

Maximum age

• 80 years

Tree form

Forest-grown

Trunk

• Long, cylindrical, smooth, with little taper
• Branch-free in the lower part

Crown

• Short, rounded

Root system

Shallow, very wide-spreading

Habitat

Site

• A great variety of soils
• Prefers sheltered sites

Associated species

• Often in pure stands; also mixed with white spruce, black spruce, balsam fir, white birch, balsam poplar and jack pine

Range

Throughout the forested areas of Canada