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Rhododendron

Rhododendron is a large genus of woody flowering plants in the heath family (Ericaceae).

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Rhododendron is a large genus of woody flowering plants in the heath family (Ericaceae). It includes evergreen and deciduous shrubs and, rarely, small to large trees, and is especially diverse in eastern Asia and the Himalayan region. Many species are grown as ornamentals for their showy flowers and foliage.

Description

Rhododendrons are woody flowering plants with attractive blossoms and, in many species, leathery leaves. They may be evergreen or deciduous, and their growth form ranges from small shrubs to trees.

Distribution and diversity

The genus is most diverse in the Himalayas and eastern Asia, especially southwest China and adjacent mountain regions. Species also occur in parts of North America, Europe, and Australia.

Cultivation

Many rhododendron species and hybrids are cultivated as ornamentals in gardens and landscapes. They are valued for their flowers, foliage, and tolerance of acidic soils.

Taxonomy

Rhododendron belongs to the heath family, Ericaceae, and is treated as a very large and morphologically diverse genus. Some classifications include azaleas within the genus rather than treating them separately.

Key facts

  • Rhododendron is one of the largest genera in the family Ericaceae.
  • Most species are native to eastern Asia and the Himalayan region.
  • The genus includes both evergreen and deciduous species.
  • Plants range from low shrubs to, rarely, large trees.
  • Rhododendrons are widely cultivated for their flowers and foliage.
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Canadian context

Rhododendrons are grown in Canadian gardens and landscapes, especially in regions with acidic soils and relatively mild, moist climates such as coastal British Columbia.

Frequently asked questions

What is Rhododendron?
Rhododendron is a genus of woody flowering plants in the heath family, Ericaceae.
Are rhododendrons evergreen?
Some are evergreen and others are deciduous.
Where are rhododendrons native to?
They are native chiefly to eastern Asia and the Himalayan region, with additional species in North America, Europe, and other areas.
Are azaleas rhododendrons?
In many modern classifications, azaleas are included within Rhododendron.
Why are rhododendrons grown in gardens?
They are widely cultivated as ornamentals because of their showy flowers and attractive foliage.

References

  1. Wikipedia — https://en.wikipedia.org/wiki/Rhododendron
    Supports: Genus size, family, growth habit, native range, and diversity
  2. Encyclopaedia Britannica — https://www.britannica.com/plant/rhododendron
    Supports: General description, approximate species count, native range, and ornamental use
  3. Encyclopedia.com — https://www.encyclopedia.com/plants-and-animals/plants/plants/rhododendron
    Supports: Morphological description, cultivation, and nectar toxicity note
  4. Britannica Kids — https://www.kids.britannica.com/students/article/rhododendron/276716
    Supports: Species count, distribution, and inclusion of azaleas in Rhododendron
  5. Merriam-Webster — https://www.merriam-webster.com/dictionary/rhododendron
    Supports: Dictionary definition of the genus as shrubs and trees with showy flowers