Black cottonwood
Description
Leaves
Form
- Broadly ovate, tip long drawn-out
- Base usually rounded, sometimes wedge-shaped or slightly heart-shaped
- No warty glands at the base
- Lower surface mostly hairless
Length
- 7–12 cm
Colour
- Upper surface dark green
- Lower surface silvery green, usually stained with brownish resin blotches
Margin
- Finely toothed with many short, rounded teeth that turn inward at their tips (sometimes partially smooth)
Petiole
- Hairy
- Round in cross-section
- 3–4 cm long
- Green
Buds
Form
- Terminal bud round or slightly angled
- Slender, long-pointed
- Very resinous, fragrant
- 6–7 scales, sometimes fringed with hairs
- Lateral leaf buds parallel to the twig
- Pollen flower buds stout with thickened scales
- Leaf scars small, triangular
Length
- 17–20 mm
Colour
- Orange-brown
Twigs
Form
- Moderately stout, hairy
- Round to slightly angular in cross-section
- Lenticels large, sparse
Colour
- Orange-brown
Flowers
Length
- Pollen catkins 4–5 cm
- Seed catkins 6–8 cm
Structure
- Dioecious
Fruits
Form
- Mature seed catkins hairy, bearing many closely spaced capsules
- Capsules nearly globular, tip short
- Covered with short hairs
- Splitting into 3 parts when mature
Length
- Mature seed catkins 12–15 cm
- Capsules 3–4 mm
- Seeds 2 mm
Bark
Form
- Smooth when young, with age separating into flat-topped ridges with irregular V-shaped furrows
Colour
- Greyish-green or yellowish-grey when young, becoming dark greyish-brown
Size
Height
- To 35 m
- The largest broadleaf tree native to British Columbia
Diameter
- To 120 cm
Maximum age
- 165 years
Tree form
Forest-grown
Trunk
- Long, straight
Crown
- Narrow, somewhat columnar
- Open, with a few stout ascending branches
Root system
- Wide-spreading, with a few large roots, penetrating obliquely to the water table or a layer of hardened soil
Habitat
Site
- At lower and middle elevations
- On bottomlands
- Loose, porous, sandy or gravelly soils
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
