Epidendroideae is a sub-family of the Orchidaceae family.
It is larger than all the other sub-families of orchids together with more than 15,000 species, divided into 15 tribes and 576 genera, or 75% of all orchid species.
Most Epidendroideae are epiphytic, usually with pseudo-bulbs. A few are terrestrial orchids and a smaller number are myco-heterotrophic, i.e. parasitic on mycorrhizal fungi.
Epidendroideae contains orchids with a single fertile anther, fully incumbent to suberect. The incumbent anther forms a right angle with the column axis or is pointed backwards.
Most have hard pollinia, i.e. a mass of waxy pollen or coherent pollen grains. The pollinia sometimes have a caudiculum (fine pedestal) and viscidium (adhesive disc).
The stigma is entire or three-lobed and possesses a rostellum (beak-shaped protrusion). The apical part (towards the top) of the center stigma lobe forms a stipum (pollinium handle). The ovary is monolocular.
The leaves are alternate or in spiral, sometimes opposed. They are distichous or spiraling, growing on thickened stems. They are usually fleshy or leathery, rarely conical or grooved, with a basal sheath, often articulated at the base.
They usually possess a pseudo-bulb and rhizomes which can be rather long.
The classification system according to the APG III (2009) is the most recent one and includes the following tribes:
This classification replaces the APG II classification (2003) of Epidendroideae which was divided into higher and lower Epidendroideae.
As this sub-family is very difficult to identify and classify, new research – and especially genetic research – will probably bring new data that will cause changes to the classification.
From DNA tests it appears that similar species are not actually related and that other were related though there were morphological differences that are caused by the different growing conditions.
Epidendroideae are found all around the globe, except at the poles.
Most Epidendroideae are epiphytes that grow in trees. Sometimes they are terrestrial.
Epidendroideae: from the Greek epi (on, above) and dendron (tree).
As this sub-family grows all around the globe and in different climates, care varies.
Sowing and division of the rhizome.