Red alder
Description
Leaves
Form
- Oval to rhombic, tapered from the middle to both ends
- Thick, not sticky
- Veins hairy on lower surface
- 8–15 veins per side, impressed on upper surface
- Veinlets forming a ladder-like pattern
- Considerable leaf-fall during summer
Length
- 7–13 cm
Colour
- Upper surface dull dark green
- Lower surface greyish
Margin
- Double-toothed, the largest teeth almost lobe-sized
- Margin clearly rolled under
Buds
Form
- 2 or 3 hairy scales that meet along their edges
- Leaf scars with 3–5 vein scars
Colour
- Green
Twigs
Form
- Moderately stout
- Triangular or round in cross-section
- Pith indistinctly triangular in cross-section
Colour
- Purplish-brown
Flowers
Form
- Pollen catkins in small clusters at the shoot tips
- Seed catkins visible in winter in small lateral clusters
Length
- Pollen catkins about 3 cm in winter, 10–15 cm at pollination
- Seed catkins about 5 mm
Structure
- Monoecious
Fruits
Form
- Mature seed catkins short-stalked, abundant
- Nutlet narrow-winged or encircled by wing
Length
- Mature seed catkins 15–25 mm
- Nutlet about 2 mm
Timing
- Ripen in early autumn, shed in late autumn and into winter
Bark
Form
- Smooth, occasionally shallowly furrowed, with age separates into irregular flat plates
Colour
- Light grey, usually almost white with lichens
- Wounds turn red
Wood
Texture
- Fine, even-textured
Colour
- Light brown, often turns reddish after cutting
Uses
- Wood carving, furniture, firewood
Size
Height
- To 25 m
Diameter
- To 60 cm
Maximum age
- 75 years
Tree form
Forest-grown
Trunk
- Straight, slightly tapered
- Distinct to top of the crown
Crown
- Narrow, rounded
Open-grown
Crown
- Extends to the ground
- Broadly conical
Root system
- Shallow, wide-spreading
Habitat
Site
- Floodplains and along streams
Light tolerance
- Intolerant of shade
Associated species
- In pure stands; also mixed with black cottonwood, grand fir, Douglas-fir, western redcedar, western hemlock, western yew, bigleaf maple, and vine maple
Range
In Canada, a narrow band within 150 km of the Pacific coast; in the United States, the states of Washington and Oregon
Insects and diseases
Insects
Insects and diseases that are found most frequently and/or that cause the most damage in our Canadian forests.
Distribution map

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