Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California and Nevada, east to Idaho.
Habitat: Near streams at low elevations.
Flowers: January-April
Origin: Native
Growth Duration: Perennial
Conservation Status: Not of concern
Pollination: Wind
Monoecious, deciduous small trees 5-20 m. tall, the old bark light-colored, the new growth puberulent.
Leaves alternate, simple, the blades elliptic or oblong-rhombic, 4-8 cm. long, acute to rounded at each end, finely to coarsely once- or twice-serrate, not wavy, hairy at least beneath, the upper surface deeper green.
: Catkins developing before the leaves on growth of the previous season; staminate catkins slender, pendulous, 4-8 cm. long, the stamens usually 2 per flower; pistillate catkins cone-like, woody, 10-15 mm. long, on stout peduncles often as long as the catkin.
Nutlet thin-margined but without a true wing.
PNW Herbaria: Specimen records of Alnus rhombifolia in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Alnus rhombifolia checklist entry
OregonFlora: Alnus rhombifolia information
E-Flora BC: Alnus rhombifolia atlas page
CalPhotos: Alnus rhombifolia photos