Azaleas are flowering shrubs in the genus Rhododendron, particularly the former sections Tsutsusi (evergreen) and Pentanthera (deciduous). Azaleas bloom in the spring, their flowers often lasting several weeks. Shade tolerant, they prefer living near or under trees. They are part of the family Ericaceae.

Rhododendron is a very large genus of about 1,024 species of woody plants in the heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan region, but smaller numbers occur elsewhere in Asia, and in North America, Europe and Australia.