[Alders: The Genus Alnus in the Columbia River Gorge 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

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

Close-up of the dorsal leaf surface of red alder. Note the large, coarse teeth with smaller teeth along the outer margin of the leaf blade.

In-rolled leaf margin along the outer edge of the ventral leaf surface of Oregon Alder, Red Alder: Alnus rubra (Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta)

Note the in-rolled leaf margin along the edge of the ventral leaf surface.

Female catkin of Oregon Alder, Red Alder: Alnus rubra (Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta) - Male catkin of Oregon Alder, Red Alder: Alnus rubra (Synonyms: Alnus oregona, Alnus oregona var. oregona, Alnus oregona var. pinnatisecta, Alnus rubra var. pinnatisecta)

The small female catkin (photo at left) and several male catkins (photo at right) of red alder as seen along the Eagle Creek Trail, Columbia River Gorge...........March 26, 2012. Both are found as part of the at the new years growth at the tips of the twigs. The smaller female catkin is usually found near the base of the male catkins.
Paul Slichter