[Alders: The Genus Alnus in the Columbia River Gorge of Oregon and Washington]

California Alder, White Alder

Alnus rhombifolia

Synonym: Alnus rhombifolia var. bernardina

California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

White alder beginning to bloom at left along the east bank of the Deschutes River, Deschutes River State Recreation Area......January 16, 2023. The photo at right shows white alders with catkins forming along the east bank of the Klickitat River, several miles downstream from Pitt, WA.....December 8, 2023.

Dorsal leaf surface of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

The photo above shows a close-up view of the upper leaf surface of white alder from the shoreline of the Deschutes River in the eastern Columbia River Gorge........Spetember 1, 2007.

California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

Male catkins of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - Male catkins of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - Close-up of the male catkins of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - Close-up of the male and female catkins of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

Additional close-up photos of white alder as seen from both the eastern and western shorelines of the Deschutes River about one-quarter mile upstream of the Columbia River.........February 11, 2012. A close-up of the female catkins can be seen in the photo at lowerrightt. They tend to be much smaller than the male catkins, bloom later and tend to be found on side branches just upstream from the terminal male catkins. Note the red styles exserted between the scales of the female catkins. White alder blooms earlier (January to April) than the similar mountain alder (Alnus incana - March to May)

Close-up of the female cones of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

A close-up of the female cones of white alder in flower along old highway 8 near the Labyrinth, central Columbia River Gorge........February 15, 2012.


California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

Male and female catkins of white alder in bloom along the Deschutes River, Deschutes River State Campground......January 29, 2021.

Female cones of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - Male cones of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

The photo above shows a close-up view of the female catkins of white alder as seen from the shoreline of the Deschutes River in the eastern Columbia River Gorge....................Spetember 1, 2007. These will mature and release seeds during the following season. Note the male catkins which are beginning to form. These catkins form in the fall and will begin to flower by late January at lower elevations in the Gorge. Note that each plant contains both male and female catkins.

Dorsal leaf surface of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

Another view of the upper leaf surface of white alder from the shoreline of the Deschutes River in the eastern Columbia River Gorge.........Spetember 1, 2007.

California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

Male catkins of white alder nearly ready to release their pollen in late January. Photographed along the east bank of the Deschutes River near MP 3.0.......January 28, 2011. Note last year's female catkins present on some of the branches. This species blooms before any leaves form.

California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - Leaf bud of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina) - Male catkings of California Alder, White Alder: Alnus rhombifolia (Synonym: Alnus rhombifolia var. bernardina)

Male and female catkins preparing to bloom and a leaf bud of white alder as seen at left and center along the east bank of the Deschutes River about one mile upstream from its junction with the Columbia River...........February 19, 2013. The photo at right shows the male catkins of white alder in bloom along the Klickitat Trail about two miles north of Lyle, WA......January 25, 2019.

Paul Slichter