r. occidentale -
              native azalea species
R. occidentale

Native Rhododendrons & Azaleas

American Rhododendron Society
Southwest Oregon Chapter

Chapter Meetings

include discussion about all kinds of native and non-native rhododendrons and places where you can find them. 
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What is a rhododendron  vs. an azalea?

Azaleas were once a genus of their own and quite separate from rhododendrons. In 1834 Azaleas were combined into the genus rhododendron and now make up two of the eight plant sub-categories (one for evergreen and another for deciduous) in the genus rhododendron.

There are no absolute guidelines for distinguishing all azaleas from all rhododendrons. There are always a few exceptions. Generally, rhododendrons have 10 or more stamens (2 per lobe). Azaleas usually have 5 stamens or 1 per lobe.

 All azaleas are rhododendrons, but not all rhododendrons are azaleas. 

There are two native rhododendrons and one azalea in the Pacific Northwest. Two these plants are deciduous, meaning they lose most (if not all) of their leaves in the winter. The other keeps it's leaves for three or more years. 

R. albiflorum is an upright shrub found in the mountainous areas. The blooms are bell shaped and typically white or yellow. This plant is difficult to grow, does not transplant well from the wild, and may not bloom dependably. Not typically available in the trade. Deciduous.

R. macrophyllum, however, is a block-buster bloomer with large white to deep pinky-purple (some even a bit red!) trusses. The trusses may include up to 20 two-inch flowers held in a loosely dome-shaped truss. Leaves are medium-large and lance-shaped. This upright shrub can grow into a small tree and can be found happily growing along Highway 101, particularly near Florence. This plant can be purchased for your garden. 

Unlike the East Coast of the United States, there is only one native azalea. R. occidentale (pictured above left). The western azalea, or California azalea, is a very variable species that is found near the coast regions from California to southern Washington. A major swarm (and a preserve) of these plants can be found near Eureka, California northward through southern Oregon. These plants can grow to be nearly 10 feet tall, have a blizzard of predominantly white, scented flowers some of which may be double and up to 5-inches across.  This plant can be purchased for your garden.

ARS logo

R. macrophyllum in the wild
R. macrophyllum in the wild.  

To learn more see:
--Greer's Guidebook to Available Rhododendrons
--The Encyclopedia of Rhododendron Species
--The American Rhododendron Society home page at: www.rhododendron.org