Description
They are native throughout southeast Asia from the Himalayan mountains to the islands of Polillo, Palawan and Zamboanga del Norte in the island of Mindanao in the Philippines and northern Australia. Orchid Island of Taiwan is named after this genus. Little recent information about their habitat and their ecology in nature is available since little field research has been done in the last decades.
Most are epiphytic shade plants; a few are lithophytes. In the wild, some species grow below the canopies of moist and humid lowland forests, protected against direct sunlight; others grow in seasonally dry or cool environments. The species have adapted individually to these three habitats.