Any plant of certain species of the genus Rhododendron ( heath family ), formerly given the generic name Azalea .
Though some gardeners consider azaleas distinct from rhododendron s, distinguishing characteristics of the two groups are not consistent enough to separate them into two genera. Azaleas typically are deciduous (see deciduous tree ), with flowers that are funnel-shaped, somewhat two-lipped, and often fragrant. Cultivated varieties have been bred from species native to the hilly regions of Asia and North America. Well-known North American kinds include the smooth, or sweet, azalea ( R. arborescens ); the flame azalea ( R. calendulaceum ); and the pinxter flower ( R. periclymenoides ).