Mountain paper birch

Leaves

Form

• Tip taper-pointed
• Base usually heart-shaped
• Upper surface has numerous tiny resin dots
• Veins 7–9 per side

Length

• 6–12 cm

Colour

• Upper surface dull green

Margin

• Double-toothed

Buds

Form

• Ovoid, blunt
• Scales resinous

Length

• 4–6 mm

Twigs

Form

• Warty resin glands

Colour

• Yellowish-brown to dark brown
• Lenticels light grey

Flowers

Form

• Pollen catkins in clusters of 2–4
• Seed catkins often pendulous

Length

• Pollen catkins 2–4 cm, up to 10 cm at pollination
• Seed catkins 1–2 cm

Width

• Pollen catkins 3–6 mm in winter

Colour

• Stigmas pale or transparent

Structure

• Monoecious

Fruits

Form

• Scales fringed with hairs
• Middle lobe with parallel sides, rounded tip

Length

• Mature seed catkins 3.5–5 cm
• Nutlets 2–3 mm
• Stigmas may be as long as the nutlet
• Scales 6–8 mm
• Middle lobe much longer than the two upright, rounded lateral lobes

Width

• Nutlets half as wide as long
• Wings much wider than nutlets

Bark

Form

• Separates into several thin layers
• Peels freely, giving the trunk a ragged look

Length

• Lenticels up to 70 mm, average 19 mm

Colour

• White or bronze-white
• Inner surface copper-coloured

Size

Height

• To 25 m

Diameter

• To 70 cm

Tree form

Forest-grown

Crown

• Broad
• Principal branches nearly horizontal

Habitat

Site

• In cooler habitats
• On upper elevations at the tree line in the southern part of its range
• On cooler northern aspects and in depressions toward the northern part of its range

Associated species

• A wide range of tree species in mixed broadleaf and conifer forests

Range

Common in Newfoundland, New Brunswick, Nova Scotia, the Gaspé Peninsula, and northern Quebec; occurs in northwestern Ontario from Sault Ste. Marie westward to Algoma District and western Lake Superior; southward through northern New York state and New England