Rhododendron (; pl.: rhododendra), from Ancient Greek ῥόδον (rhódon), meaning "rose", and δένδρον (déndron), meaning "tree", is a very large genus of about 1,024 species of woody plants in the heath family (Ericaceae). 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 and Jiangxi in China, and the state tree of Sikkim and Uttarakhand in India. Most species have brightly coloured 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.
Description
Rhododendron in the Carpathian Mountains of Western Ukraine
Rhododendron is a genus of shrubs and small to (rarely) large trees, the smallest species, R. cespitosum of New Guinea, growing to 10–100 cm (4–40 in) tall, and the largest, R. protistum var. giganteum, reported to 30 m (100 ft) tall. The leaves are spirally arranged; leaf size can range from 1–2 cm (0.4–0.8 in) to over 50 cm (20 in), exceptionally 100 cm (40 in) in R. sinogrande. They may be either evergreen or deciduous. In some species, the undersides of the leaves are covered with scales (lepidote) or hairs (indumentum). Some of the best known species are noted for their many clusters of large flowers. A recently discovered species in New Guinea has flowers up to six inches (fifteen centimeters) in width, the largest in the whole genus. The accompanying photograph shows it as having seven petals. There are alpine species with small flowers and small leaves, and tropical species such as section...
