Rhododendrons are an attractive group of plants, most have large showy flowers, sometimes beautifully scented and they are of considerable horticultural importance in many parts of the world. The genus Rhododendron consists of about nine hundred species with majority coming from the Himalayan Region from Northern India, through Nepal, into western China. A small group has spread around the temperate and arctic regions of the northern hemisphere and penetrated south into North America but Rhododendrons are absent from South America, Africa and except for one species, from Australia.
Vireya Rhododendrons occur predominently in the South-East Asian islands and Malay Peninsula (West Malaysia) and number nearly three hundreds species or about one third of the genus. Over half this number are recorded from the island of New Guinea but Borneo possesses some fifty species with thirty-five of these having so far been found in Sabah. Twelve species are endemic to Sabah and have been found nowhere else and Kinabalu, easily the richest single mountain in Sabah, has twenty-five species growing on its slopes, five of them not known from any other mountain.