The following taxonomy follows largely the classification system of Robert Louis Dressler, an orchid specialist and adjunct curator at the Florida Museum of Natural History. This classification, published in the book The Orchids: Natural History and Classification, is widely accepted by botanists and growers. The initial scheme of 1981 has been modified in 1986, twice in 1990. and then again in 1993. This is the most comprehensive classification at the moment. But it relies heavily on morphology and a few key characters, such as anther configuration and pollinarium structure.
According to morphological cladistics and research with rbcL nucleotide sequences, the orchid family, as well as the clades within the family, are a monophyletic group. There is a great similarity with the traditional taxonomy, except for the Vandoideae, but on lower levels, matters are still unresolved. Few tribes, as circumscribed here below, are monophyletic. Cladistic and molecular methods give us a firmer basis, but the classification is still an ongoing issue. There is even no strong support for the interelationships of the subfamilies. Furthermore, about 150 species and even new genera are still being discovered each year.
