red alder (Alnus rubra)

• Leaves: Simple, alternate, and deciduous; egg-shaped; 3"-6" long; margins doubly serrated and tightly rolled under; veins very straight.

• Fruit: Small brown woody "cones" about 1" long.

• Twigs: Young twigs are triangular in cross-section. Buds are borne on short stalks.

• Distribution: Found in cool, moist environments below 2,500 ft. west of the Cascades.
  

white alder (Alnus rhombifolia)

(click on each photo to enlarge image)

• Leaves: Simple, alternate, and deciduous; egg-shaped; 2"-4" long; margins serrated or doubly serrated; not rolled under; veins very straight.

• Fruit: Small brown woody "cones" about 1" long.

• Twigs: Have stalked buds.

• Distribution: Found on both sides of the Cascades, especially along streams; grows from British Columbia through much of California and into Idaho and Montana.

For more information about these species see "Trees to Know in Oregon".