[ Alders: The Genus Alnus in the Cascade Mountains of Oregon and Washington]

Oregon Alder, Red Alder

Alnus rubra

Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta

Leaves of Oregon Alder, Red Alder: Alnus rubra (Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta)

Upper leaf surface of Oregon Alder, Red Alder: Alnus rubra (Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta)

The photo above shows the leaf of red alder at a small creek at about 2720' along Rd K6000 at the southeastern side of Mt. Adams........July 10, 2005. Existing as a large shrub or small tree, the leaves of red alder are darker green above, and pale rusty-gray below. The margins are rolled under with broad triangular teeth which may in turn bear several smaller teeth. The catkins appear before the leaves do.

Lower leaf margin of Oregon Alder, Red Alder: Alnus rubra (Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta)

The photo above shows the revolute margin to the underside of a red alder leaf. This means that the margin is slightly rolled under. Photographed along the upper Klickitat River about 7 miles southeast of Glenwood,WA.........May 26, 2008.
Paul Slichter