The Orchidoideae, or the orchidoid orchids, are a subfamily of the orchid family (Orchidaceae) that contains around 3630 species. Species typically have a single (monandrous), fertile anther which is erect and basitonic.
Description
The subfamily Orchidoideae and the previously recognized subfamily Spiranthoideae are considered the closest allies in the natural group of the monandrous orchids because of several generally shared characters:
- a shared terrestrial habit
- sectile (capable of being severed) or granular pollinia
- erect anthers.
Taxonomy
Phylogeny of the Orchidoideae is volatile and still subject to change. Historically, the Orchidoideae have been partitioned into up to 6 tribes, including Orchideae, Diseae, Cranichideae, Chloraeeae, Diurideae, and Codonorchideae. However, the most recent molecular phylogenetics analysis led by Chase et al. in 2015 and subsequently by Chen et al. in 2017 indicates that the Orchidoideae should be split into 4 tribes: the Orchideae, Cranichideae, Diurideae, and Codonorchideae.
Codonorchideae
This monophyletic tribe consists of only one genus, Codonorchis, found in South America. (a nonsystematic paraphyletic splitting), the Orchideae now comprise 6 subtribes.