A variety of tropical orchids grow on the ground, as do our native species.For nutrient intake, the plant drills its roots into the soil.Terrestrial orchids have it easier to get to the nutrients and (ground) water.Nutrients are more or less continuosly available.
Lithophytic
A small group of orchids even grow on rocks,the plant clings to the surface with its roots.They get nutrients from the air and from deposits (moss,minerals etc.)
Epiphyte
Lack of light on the ground is the reason for the evasion of Trees and Shrubs. Most tropical orchids grow in forked branches and in treetops because the light is best there. The plants get their nutrients from the air and the humus wich collects in the tree bark and branches. To do this it needs special skilled roots.
