The genus Dendrobium includes a great number of species found over a vast range of territory: over 1,800 species found throughout Asia, from India to Korea, throughout Southeast Asia, to Australia, and throughout the Pacific Islands. The genus offers across those 1,800 species and its thousands of hybrids an almost inconceivable amount of floral diversity, from the rugged, drought-tolerant Dendrobium speciosum of Australia, with its enormous showy sprays of fragrant flowers, to the diminutive Dendrobium cuthbertsonii of the cool highlands of Papua New Guinea, whose miniscule leaves disappear beneath a dome of brightly colored crimson flowers that can last six months! Many Dendrobiums are evergreen, while others (such as those in the Nobile Section) are annually deciduous, and will only bloom on leafless canes. While the most commercially popular Dendrobiums available have a leafed, cane-like growth form, this genus displays a tremendously varied morphology across species. This great diversity of forms is a result of the specific adaptations of Dendrobium species. While some species are very common across Asia, and have ranges that extend across several countries, others have evolved to occupy highly specific ecological niches, and might be endemic to a single mountain range. Dendrobiums are found in places as different from each other as hot, coastal lowland swamps, to high-elevation cloud forests, and therefore, care requirements and blooming habits vary greatly across the genus.