Water birch

Silhouette - water birch
  • Latin name: Betula occidentalis Hook.
  • French name: Bouleau fontinal
  • Synonym(s): Western birch , river birch , red birch , black birch
  • Taxonomic Serial Number: 19488
    195216 [syn. B. fontinalis Sarg.]
Description

Leaves

  • Leaf with detail of  distinct double-toothed margin - water birch

Form

  • Small, broadly oval, or widest below the middle
  • Tip wedge-shaped, blunt, or sharp
  • Base rounded or wedge-shaped
  • Upper surface shiny
  • Tiny resin dots on lower surface
  • Veins 4 or 5 per side

Length

  • 2–5 cm

Colour

  • Upper surface deep yellowish-green
  • Lower surface lighter yellowish-green

Margin

  • Base has a smooth margin
  • Each vein ends in a large tooth, with 3 or 4 small intervening teeth
  • Teeth sharp, of 2 distinct sizes

Petiole

  • Hairy

Buds

  • Lateral bud and leaf scar - water birch

Form

  • Pointed, slightly resinous

Colour

  • Greenish-brown

Twigs

  • Winter twig - water birch

Form

  • Very slender, often hairy

Colour

  • Reddish-brown with many reddish warty resin glands

Flowers

Length

  • Pollen catkins about 2 cm in winter, 6 cm at pollination
  • Seed catkins about 2 cm

Structure

  • Monoecious

Fruits

  • Fruit scale (left); winged nutlet (right) - water birch

Form

  • Mature seed catkins slender, pendulous
  • Nutlet hairy
  • Lateral lobes angled upward, shorter than the middle lobe

Length

  • Mature seed catkins 2.5–4 cm
  • On stalks 1–2 cm

Width

  • Nutlet about as wide as the wings

Margin

  • Scales hairy with pointed lobes

Bark

Form

  • Thin, lustrous
  • Not peeling readily
  • Lenticels long

Colour

  • Dark to nearly black when young, with age becoming purplish-brown

Size

Height

  • To 12 m

Diameter

  • To 30 cm

Tree form

  • Silhouette - water birch

Forest-grown

Trunk

  • Leaning, crooked

Crown

  • Open, with upright branches drooping at the tips

Habitat

Site

  • Moist soils along streams

Associated species

  • Poplars, willows, and alders
  • Dense, pure thickets are common

Range

Hudson Bay to interior British Columbia

Photos
  • Water birch
Distribution map
Distribution map - water birch
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