page_title: List of Rhododendron species
section_title: O
hierarchical_section_title: List of Rhododendron species / O
caption_attribution_description: Rhododendron occidentale, photographed at the San Francisco Botanical Garden at Strybing Arboretum
context_page_description: This List of Rhododendron species includes species of the genus Rhododendron, which is in the plant family Ericaceae. Depending on the source, there are anywhere from 800 to over 1,100 wild species. The vast majority of Rhododendron species are native to the eastern Himalaya and southeast Tibet, along with the islands of Java, Sumatra, Borneo, New Guinea, and the Philippines. The rest are broadly spread throughout the northern hemisphere in relatively small isolated populations, including Japan, northwestern North America, the Appalachian, and the Caucasus Mountains.
  Rhododendron has eight traditionally accepted subgenera based on morphology, still the consensus taxonomy used by most authorities: Azaleastrum; Candidastrum; Hymenanthes; Mumeazalea; Pentanthera; Rhododendron; Therorhodion; Tsutsusi. Hymenanthes, with approximately 225 species, and subgenus Rhododendron, with approx. 400 species, comprise what gardeners typically describe as "Rhododendrons." Two subgenera are generally known to gardeners as "Azaleas", and include many fewer true species: Pentanthera, which comprises the deciduous azaleas, and Tsutsusi, which includes evergreen azaleas.
context_section_description: Rhododendron oblancifolium M.Y. Fang
  Rhododendron oblongifolium (Small) Millais
  Rhododendron obtusum (Lindl.) Planch.
  Rhododendron occidentale (Torr. & A. Gray) A. Gray
  Rhododendron ochraceum Rehder & E.H. Wilson
  Rhododendron octandrum M.Y. He
  Rhododendron oldhamii Maxim.
  Rhododendron oligocarpum W.P. Fang
  Rhododendron orbiculare Decne.
  Rhododendron oreodoxa Franch.
  Rhododendron oreogenum L.C. Hu
  Rhododendron oreotrephes W.W. Sm.
  Rhododendron orthocladum Balf. f. & Forrest
  Rhododendron ovatum (Lindl.) Planch. ex Maxim.
caption: Rhododendron occidentale
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