Sitka alder

Leaves

Form

• Broadly oval, thin
• Resinous and fragrant when young
• Mostly hairless
• Base broad, often asymmetrical
• 6–8 veins per side
• Veinlets irregularly branched

Length

• 7–15 cm

Colour

• Shiny, deep yellowish-green

Margin

• Teeth sharp, gland-tipped, of 2 sizes, none near the petiole
• Each vein ends in a large tooth

Buds

Form

• Curved, sharp-pointed, stalkless
• 3–5 overlapping scales
• Usually arranged in 2 ranks along the twig
• Leaf scars raised, crowded along the twig

Length

• 12–14 mm

Colour

• Purplish-brown

Twigs

Form

• Slender, sticky when young
• Dwarf shoots may develop

Colour

• Light reddish-brown or yellowish-brown with pale lenticels

Flowers

Form

• Pollen catkins stalkless, in pairs
• Seed catkins enclosed in a bud in winter

Length

• About 1 cm in winter, 10–14 cm at pollination

Timing

• Open with the leaves

Stucture

• Monoecious

Fruits

Form

• Several mature seed catkins in an erect cluster

Length

• 12–20 mm with equally long stalks

Width

• Nutlet about the same width as wings

Bark

Form

• Smooth with long horizontal lenticels

Colour

• Reddish- to greyish-brown

Size

Height

• To 15 m

Diameter

• To 20 cm

Tree form

Forest-grown

Trunk

• Slender

Crown

• Open, with short horizontal branches

Root system

• Shallow

Habitat

Site

• Cool moist sites in the mountains
• Often where landslides have created openings

Range

From the Pacific Coast to the western slopes of the Rocky Mountains