Most advanced Orchids have five basic features
1. The presence of a column : call gynostemium.
2. The flower is bilaterally symmetric
3. The pollen are glued together into the pollinica, a mass of waxy
pollen on filament.
4. The seeds are microscopically small (exception Disa & Vanilla)
5. The seeds can, under natural circumstances, only germinate in
symbiosis with specialized fungi