Χρήστης:Vchorozopoulos/ορχιδέες

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, some matters are still unresolved. Few tribes, as listed 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.

The orchid family (Orchidaceae) is subdivided in several subfamilies, and then in tribes, subtribes, alliances and then genera.

According to Dressler, there are 5 subfamilies, 22 tribes, 70 subtribes, about 850 genera and about 20,000 species in this family.

The following subfamilies are recognized:

Subfamily Apostasioideae: monophyletic - the most primitive orchids : 3 fertile anthers or two fertile anthers and a filamentous staminode. Subfamily Cypripedioideae: monophyletic - 2 fertile diandrous anthers, a shield-shaped staminode and a saccate (= pouch-like) lip. Subfamily Orchidoideae: single, fertile monandrous, basitonic anther. (Subfamily Spiranthoideae): nested within a more broadly defined Orchidoideae Subfamily Epidendroideae: includes almost 80% of the orchid species; monophyletic; orchids with an incumbent to suberect ( = ascending towards the edges) anther. (Subfamily Higher Epidendroideae (formerly Vandoideae) : specialised clade within a more broadly defined Epidendroideae Subfamily Vanilloideae: an ancient clade now recognized as a distinct subfamily. But, from a molecular point of view, it is rather a sister to subfamily Epidendroideae + subfamily Orchidoideae. This subfamily is a branch at the basal dichotomy of the monandrous orchids. As the Genera Orchidacearum (Pridgeon, A.M., Cribb, P.J., Chase, M.A. & Rasmussen, F.; Oxford Univ. Press.) will only be completed in 2006-2007, and changes in taxonomy of orchids are so frequent, the following taxonomy still follows largely the system of Robert Louis Dressler.