Rhododendron is a genus of a shrub with about 800 species worldwide. Its ovate evergreen or deciduous leaves are alternate, 1/2 - 8 inches in length depending on variety, with smooth untoothed margins. They are dark green with a glossy upper surface and a dull underside. Large trusses of bell-shaped flowers bloom from spring to early summer. Plants are available with flowers in colors such as white, purple, deep rose, red, yellow, and orange. Rhododendron and its closely related azalea have been hybridized for many uses in gardens'.