Rhododendron (; from Ancient Greek rhódon "rose" and déndron "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 in India, 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. Species Description Rhododendron is a genus of shrubs and small to (rarely) large trees, the smallest species growing to tall, and the largest, R. protistum var. giganteum, reported to tall. The leaves are spirally arranged; leaf size can range from to over , exceptionally 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. There are alpine species with small flowers and small leaves, and tropical species such as section Vireya that often grow as epiphytes. Species in this genus may be part of the heath complex in oak-heath forests in eastern North America. They have frequently been divided based on the presence or absence of scales on the abaxial (lower) leaf surface (lepidote or elepidote). These scales, unique to subgenus Rhododendron, are modified hairs consisting of a polygonal scale attached by a stalk. Rhododendron are characterised by having inflorescences with scarious (dry) perulae, a chromosome number of x=13, fruit that has a septicidal capsule, an ovary that is superior (or nearly so), stamens that have no appendages, and agglutinate (clumped) pollen. Taxonomy Rhododendron is the largest genus in the family Ericaceae, with over 1000 species, (though estimates vary from 850 to 1200) and is morphologically diverse. Consequently, the taxonomy has been historically complex. Early history Although Rhododendrons had been known since the description of Rhododendron hirsutum by Charles de l'Écluse (Clusius) in the sixteenth century, and were known to classical writers