Speckled alder

Silhouette - speckled alder
Silhouette - speckled alder
  • Latin name: Alnus incana ssp. rugosa (Du Roi) J. Clausen
  • French name: Aulne rugueux
  • Synonym(s): Tag alder , hoary alder , gray alder
  • Taxonomic Serial Number: 181888
    19475 [syn. A. rugosa (Du Roi) Spreng.]
Description

Leaves

  • Leaf with details of double-toothed margin (above) and prominent  veins on lower surface (below) - speckled alder

Form

  • Oval, thick-textured, not sticky
  • Upper surface wrinkled, veins deeply impressed
  • Lower surface hairy, prominent veins
  • Veinlets forming a ladder-like pattern
  • Considerable leaf-fall during the summer

Length

  • 5–10 cm

Colour

  • Upper surface dull green
  • Veins on lower surface brownish-red

Margin

  • Double-toothed

Buds

Form

  • Blunt, stalked, with 2 or 3 scales that meet along their edges
  • Arranged in 3 ranks along the twig

Colour

  • Dark reddish-brown

Twigs

  • Lateral bud and leaf scar - speckled alder
  • Winter twig - speckled alder

Form

  • Moderately slender

Colour

  • Brown

 

Flowers

  • Pollen catkin in winter condition - speckled alder

Form

  • Immature seed catkins visible in winter

Length

  • Pollen catkins 1–2.5 cm in winter, 5–8 cm at pollination
  • Immature seed catkins 2–5 mm

Structure

  • Monoecious

Fruits

  • Fruit scale (left); nutlet (right) - speckled alder

Form

  • Mature seed catkins ovoid to globular, short-stalked
  • In pendulous clusters
  • Nutlets very narrow-winged

Length

  • Mature seed catkins 13–16 mm

Bark

Form

  • Smooth

Colour

  • Reddish-brown with conspicuous horizontal orange lenticels

Size

Height

  • To 8 m

Diameter

  • To 12 cm

Tree form

  • Silhouette - speckled alder
  • Silhouette - speckled alder

Forest-grown

Trunk

  • Clumped, crooked

Habitat

Site

  • Moist sites such as stream banks and swamps

Light tolerance

  • Intolerant of shade

Associated species

  • Often mixed with black spruce or eastern white-cedar

Range

Newfoundland and northeastern Quebec, south to Lake Erie, westward to central British Columbia, and northern Yukon

Insects and diseases

Insects and diseases that are found most frequently and/or that cause the most damage in our Canadian forests.

Photos
  • Speckled alder
  • Speckled alder
  • Speckled alder
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