Family: Betulaceae, Birch view all from this family

Description Medium-sized to large tree with tall, straight trunk and open, rounded crown; showy in winter with long, golden-colored male catkins hanging from slender, leafless twigs.
Height: 70' (21 m).
Diameter: 2' (0.6 m).
Leaves: in 3 rows; 2-3 1/2" (5-9 cm) long, 1 1/2-2" (4-5 cm) wide. Ovate or elliptical, finely saw-toothed but not lobed, slightly thickened, with 9-12 nearly straight, parallel veins on each side. Dull dark green, hairless or nearly so, and often with tiny gland-dots above, light yellow-green and slightly hairy beneath.
Bark: light or dark brown, fissured into flat, scaly ridges.
Twigs: slender, light green, finely hairy when young, with 3-angled pith.
Flowers: tiny; in winter and early spring before leaves. Male yellowish in drooping, narrowly cylindrical catkins 1 1/2-5" (4-13 cm) long. Female reddish in narrow cones 3/8" (10 mm) long.
Cones: 3/8-3/4" (10-19 mm) long; 3-7 clustered on short stalks, elliptical, with many hard, black scales; remaining closed until early spring; tiny, elliptical, flat nutlets; maturing in late summer.

Habitat With chaparral and Ponderosa Pine in foothill woodlands.

Range W. Idaho and Washington south in mountains to W. Nevada and S. California; at 100-8000' (30-2438 m); generally below 5000' (1524 m).

Discussion White Alder, named for its pale green foliage, is the only alder native in southern California. Limited to permanent streams, it is a good indicator of water. It is sometimes planted as an ornamental in wet sites.