''Rhododendron rex'' (大王杜鹃), the king rhododendron, is a tree

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, usually in height, in the family

Ericaceae The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it th ...

. It is found in China,

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, and

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

, where it is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. The flowers are creamy-white, or pale yellow to pink, with a crimson basal blotch. The leaves are 17–27 cm in length and are covered on the underside with an

indumentum In biology, an indumentum (Latin, literally: "garment") is a covering of trichomes (fine "hairs") on a plant Davis, Peter Hadland and Heywood, Vernon Hilton (1963) ''Principles of angiosperm taxonomy'' Van Nostrandpage, Princeton, New Jersey, pa ...

that ranges in colour from greyish to rusty brown. The

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

describes ''Rhododendron rex'' and its subspecies as very large shrubs or trees, reaching in cultivation. Three of them have received the RHS Award of Garden Merit:- *''Rhododendron rex'' *''Rhododendron rex'' subsp. ''fictolacteum'' * ''Rhododendron rex'' subsp. ''rex'' There is a further named subspecies, ''Rhododendron rex'' subsp. ''gratum''. All are hardy down to , but like most rhododendrons they require a sheltered position in dappled shade, and acid soil enriched with leaf mould.

References

External links

* H. Léveillé, ''Repert. Spec. Nov. Regni Veg.'' 13: 340. 1914.
Danish Chapter of ARS
rex Near threatened plants Taxonomy articles created by Polbot {{Ericaceae-stub