Douglas maple

Leaves

Form

• 3–5 lobes
• Narrow toward base
• Notches usually shallow, narrowing to sharp slits
• Lower surface hairless

Length

• 7–14 cm
• Petiole 3–12 cm

Width

• About as wide as long

Colour

• Upper surface dark green
• Lower surface greyish-green
• Petiole often reddish

Autumn colour

• Dull red

Margin

• Coarsely double-toothed
• Outer edges of teeth often curved outward  

Petiole

• Slender

Buds

Form

• Terminal bud present, blunt, smooth
• 1 visible pair of scales

Length

• 2–5 mm 

Colour

• Bright red, sometimes yellow

Twigs

Form

• Slender, smooth
• Often faintly many-sided in cross-section

Colour

• Light green to reddish-brown or purplish

Flowers

Form

• 5 petals in loose drooping clusters (panicles)

Width

• About 5 mm

Colour

• Yellowish-green

Structure

• Mostly dioecious
• At the end of new shoots and along the sides of the branchlets

Floral timing

• With the unfolding leaves

Fruits

Form

• Nearly parallel
• Angle between wings less than 45°
• Hairless
• Seedcase strongly wrinkled, indented
• Keys in drooping clusters
• Mature in midsummer

Length

• Wings 18–22 mm

Colour

• Often rose-coloured

Autumn colour

• Turns light brown

Structure

• Samara
• In joined pairs

Bark

Form

• Thin, smooth, rough with age

Colour

• Dark reddish-brown

Size

Height

• To 10 m 

Diameter

• To 25 cm

Tree form

Forest-grown

Trunk

• Short, with a few slender and sharply ascending limbs dividing into many branches

Crown

• Irregular, uneven-topped 

Root system

• Shallow, wide-spreading

Habitat

Site

• Along streams and on other moist sites

Range

A western tree

Other

The typical variety of this species, A. glabrum Torr. var. glabrum (TSN 28743), a tree of the Rocky Mountains in the United States, can be found in a few localities in Alberta.