Azaleas are shade-tolerant shrubs that are often found living beneath, or close to, trees. They bloom in the spring and flower in a variety of different colors. There are both evergreen (subgenus: Tsutsusi) and deciduous (subgenus: Pentanthera) species of azalea. Azalea can be found in several Asian countries as well as North America. All species of azalea native to North American are deciduous with flower colors spanning white, purple, red, pink, orange, and yellow. Azalea blooms can be more than one color at once and sometimes have stripes or speckles. The leaf and flower shape of azaleas is quite variable, leaf size ranges from 1/4 or an inch to 6 inches, the evergreens usually smaller while the deciduous varieties often sport larger leaves. Leaves are generally dark green, with the exception of some species with variegated leaves. Azalea leaves are described as "foot-ball" shaped though there are a few species with thinner leaves.
There are 17 species of azalea native to North America, however, 15 of the 17 are native to the southeastern portion of the country. Rhododendron occidentale, Western Azalea, is native to the Pacific Northwest and Rhododendron canadense, Rhodora, is native to Southeastern Canada and Northeastern United States. R. occidentale has white to pink flowers with a yellow stripe or blotch. The flowers are fragrant and grow in clusters. Its leaves are bright yellow green rounded ovals. Western Azaleas grow in riparian areas and wetlands and are tolerant of the serpentine soil found in the Klamath-Siskiyou region.