The genus Dendrobium was named by Olof Swartz in 1799. The generic epithet refers to the epiphytic habit of the majority of the species. With about 1580 species, it is the second largest orchid genus, behind only Bulbophyllum. Dendrobiums are one of the most widely distributed genera, being found as far north as Korea and Japan, throughout China, west to India and Sri Lanka, down through Peninsular Malaysia, Indonesia, Borneo, the Philippines, Guam, New Guinea, Australia and as far east as Tahiti.
The genus, when taken in the broad sense, and as represented in the Philippines, has about 110 species. In fact, the Philippines is considered one of the centres of biodiversity for the genus and its relatives. In this Guide, the authors present information on the species that have been recorded from the Philippines archipelago. The list is as up to date as possible; however, new areas are still being opened up for exploration and study, and consequently more new species of all types of orchids are continually being found and described.