The Rhododendron arboreum belongs to Ericaceae (the Azalea family). It is a tall tree that is native to the southern China, Bhutan, Nepal, Thailand, India and Sri Lanka. This tree grows in mountains forests and usually can reach up to 12 m in height. The leaves are dark-green, oblong, leathery and covered with silvery or brown hairs beneath. The red, pink or white flowers bloom in spring. They are bell-shaped and have black necter pouches and black spots inside. Rhododendron arboreum is also the national flower of Nepal.