Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Alnus rubra

Oregon alder, red alder
Habit Trees, to 28 m; trunks often several, crowns narrow or pyramidal.
Bark

gray, smooth, darkening and breaking into shallow rectangular plates in age;

lenticels inconspicuous.
Leaf

blade ovate to elliptic, 6–16 × 3–11 cm, leathery, base broadly cuneate to rounded, margins strongly revolute, deeply doubly serrate or crenate, with distinctly larger secondary teeth, apex acute to obtuse;

surfaces abaxially glabrous to sparsely pubescent.
Inflorescences

formed season before flowering and exposed during winter; staminate catkins in 1 or more clusters of 2–6, 3.5–14 cm; sistillate catkins in 1 or more clusters of 3–8.
Infructescences

ovoid to nearly globose, 1–3.5 × 0.6–1.5 cm;

peduncles 1–10 mm.
Winter

buds stipitate, ellipsoid, 6–10 mm, apex rounded, long;

stalks 2–8 mm;

scales 2–3, outer 2 equal and valvate, usually heavily resin-coated.
Flowering

before new growth in spring.
Samaras

ovate or elliptic, wings much narrower than body, irregularly elliptic to obovate, leathery.
2n

= 28.

Alnus rubra
Phenology Flowering early spring.
Habitat Stream banks, moist flood plains, lake shores, wet slopes, and sandy, open coasts
Elevation 0–300 m (0–1000 ft)
Distribution
from FNA
AK; CA; ID; OR; WA; BC; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

Alnus rubra is the largest alder in North America north of Mexico; it often forms extensive stands along streams and on low-lying flood plains in the Pacific Northwest. The strongly revolute margins of its leaf blades make it easily distinguished from all of the other alders in the flora. It is an important commercial tree; the wood is used to make inexpensive furniture, small wooden items, and paper pulp.

Native Americans used various parts of plants of Alnus rubra medicinally as a purgative, an emetic, for aching bones, headaches, coughs, biliousness, stomach problems, scrofula sores, tuberculosis, asthma, and eczema, and as a general panacea (D. E. Moerman 1986).

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 3.
Parent taxa Betulaceae > subfam. Betuloideae > Alnus
Sibling taxa
A. glutinosa, A. incana, A. maritima, A. oblongifolia, A. rhombifolia, A. serrulata, A. viridis
Synonyms A. oregona, A. rubra var. pinnatisecta
Name authority Bongard: Mém. Acad. Sci. St.-Pétersbourg, Sér. 6, Sci. Math. 2: 162. (1833)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:
Northwest Wildflowers