Rhododendron, from Ancient Greek, meaning "rose", and dendron, meaning "tree", is a very large genus of about 1,024 species of woody plants in the heath family. They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan region, but smaller numbers occur elsewhere in Asia, and in North America, Europe and Australia. It is the national flower of Nepal, the state flower of Washington and West Virginia in the United States, the state flower of Nagaland and Himachal Pradesh in India, the provincial flower of Jeju Province in South Korea, the provincial flower of Jiangxi in China and the state tree of Sikkim and Uttarakhand in India. Most species have brightly colored flowers which bloom from late winter through to early summer. Azaleas make up two subgenera of Rhododendron. They are distinguished from "true" rhododendrons by having only five anthers per flower.

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