Rhododendron is a genus of 1,024 species of woody plants in the heath family, Ericaceae, either evergreen or deciduous, and found mainly in Asia. Most species have showy flowers. The genus name is derived from the Ancient Greek words rhódon meaning rose and déndron meaning tree. Both species and hybrid rhododendrons (including azaleas) are used extensively as ornamental plants in landscaping in many parts of the world, including both temperate and sub temperate regions, while many species and cultivars are grown commercially for the nursery trade. Rhododendrons are often valued in landscaping for their structure, size, flowers, and the fact that many of them are evergreen. Azaleas are frequently used around foundations and occasionally as hedges, and many larger-leafed rhododendrons lend themselves well to more informal plantings and woodland gardens, or as specimen plants. In some areas, larger rhododendrons can be pruned to encourage more tree-like forms.

Rhododendron degronianum is a rhododendron species native to northern Honshu, Japan, where it grows at altitudes of about 1800 meters. It is a shrub that grows to 2.5 m in height when planted in open soil. It also makes a beautiful container plant and bonsai. The leaves are narrowly to broadly elliptic, or linear lanceolate. Flowers are pink fading to white. Synonyms include Azalea degroniana and Rhododendron metternichii.