Spring time is Rhododendron time around the world. These prolific bloomers are native to Asia, North America, Australia, and Europe. They are members of the Genus Rhododendron and the Family of Ericaceae (Heaths). The name is derived from ancient Greek (rhódon “rose” or “red“) and déndron “tree”). There are some 800 to 1,000 species and 28,000 cultivars listed by the Royal Horticultural Society. Azaleas are a subgenera of Rhododendron.