Family: Betulaceae, Birch view all from this family

Description Thicket-forming shrub or small tree, often with several trunks, and with shiny yellow-green leaves, gummy when young.
Height: 30' (9 m).
Diameter: 8" (20 cm).
Leaves: 2 1/2-5" (6-13 cm) long, 1 1/2-3" (4-7.5 cm) wide. Ovate, shallowly wavy-lobed and doubly saw-toothed with long-pointed teeth and 6-10 nearly straight parallel veins on each side; gummy or sticky when young. Shiny, speckled yellow-green on both surfaces, paler and often slightly hairy beneath.
Bark: gray to light gray, smooth and thin; inner bark red.
Twigs: gummy, finely hairy, and orange-brown when young; becoming light gray, slender, and slightly zigzag.
Flowers: tiny; in spring with or after leaves. Male flowers yellowish, drooping, narrowly cylindrical; in catkins 3-5" (7.5-13 cm) long, 3/8" (10 mm) wide. Female flowers reddish, in narrow cones 3/8" (10 mm) long.
Cones: 1/2-3/4" (12-19 mm) long; 3-6 clustered on slender, spreading, long stalks; elliptical, with many hard, black scales; remaining attached. Tiny, elliptical, flat nutlets with 2 broad wings; maturing in summer.

Habitat Along streams and lakes and in valleys.

Range SW. and central Alaska and Yukon southeast to NW. California and central Montana; in Alaska to alpine zone above timberline; in NW. California to 7000' (2134 m).

Discussion In Alaska, Green Alder is a pioneer in disturbed areas, following landslides, logging, and glacial retreat. Adapted to soils too barren for other trees, this species improves soil conditions by adding organic matter and nitrogen from bacteria in its root nodules. It acts as a short-lived nurse tree for Sitka Spruce, later dying when shaded by the larger conifer.