Alaska paper birch

Leaves

Form

• Triangular to broadly oval
• Tip long-tapered, sharp-pointed
• Base broadly wedge-shaped
• Tiny resin dots on lower surface, almost hairless
• Veins 4 or 5 per side

Colour

• Upper surface shiny dark green
• Lower surface light yellowish-green

Length

• 4–7 cm

Margin

• Smooth
• Teeth often gland-tipped
• Each vein ends in a tooth, with 3–5 smaller intervening teeth

Buds

Form

• Blunt, resinous, slightly hairy

Colour

• Greenish-brown

Twigs

Form

• Slender with an abundance of fine short hairs
• Covered with resin glands, sometimes large and crystalline and dense enough to conceal the twig surface

Colour

• Bright reddish-brown

Flowers

Length

• Pollen catkins 2.5–4 cm at pollination
• Seed catkins 1–2 cm

Structure

• Monoecious

Fruits

Form

• Mature seed catkins blunt-tipped, drooping or slightly spreading from the dwarf shoots
• Scales with 2 rounded lateral lobes pointing away from the central lobe or curved slightly downward

Length

• Mature seed catkins about 2.5–3.5 cm
• Nutlets twice as long as broad

Width

• Wings much wider than the nutlet

Bark

Form

• Thin, smooth
• Peels off in papery layers (not as freely as white birch)

Colour

• Dark reddish-brown when young, with age becoming creamy white or slightly pinkish

Size

Height

• To 15 m

Diameter

• To 20 cm

Tree form

Forest-grown

Crown

• Narrow, oval
• Branches slender, stiffly upright, some with drooping tips

Habitat

Site

• Bogs and poorly drained soils

Associated species

• In pure stands or mixed with other species, especially black spruce