Burke: Alnus oblongifolia vs. Alnus rhombifolia

	Alnus oblongifolia	Alnus rhombifolia
		California alder, white alder
Habit		Monoecious, deciduous small trees 5-20 m. tall, the old bark light-colored, the new growth puberulent.
Leaves		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.
Flowers		: 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.
Fruits		Nutlet thin-margined but without a true wing.

	Alnus oblongifolia	Alnus rhombifolia
Flowering time		January-April
Habitat		Near streams at low elevations.
Distribution	[WildflowerSearch map] [BONAP county map]	Occurring chiefly east of the Cascades crest in Washington; Washington to California and Nevada, east to Idaho. [WildflowerSearch map] [BONAP county map]
Origin		Native
Conservation status		Not of concern
Sibling taxa	A. glutinosa, A. incana, A. rhombifolia, A. rubra, A. viridis	A. glutinosa, A. incana, A. rubra, A. viridis
Web links	Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Alnus oblongifolia

Alnus rhombifolia

California alder, white alder

Habit

Monoecious, deciduous small trees 5-20 m. tall, the old bark light-colored, the new growth puberulent.

Leaves

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.

Flowers

: 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.

Fruits

Nutlet thin-margined but without a true wing.