Orchids grow mainly in the tropics, where fierce competition among plants has led to the diversity of growing locations where the orchid has adapted. The root systems have developed features that allow success in different and often-changing environments. An orchid clinging to a tree high up in the canopy will have greater access to light than one that's growing down on a dark forest floor.
Orchids can grow in soil, on rocks and in trees. The roots of the rock and tree dwellers cling tightly to the surface and are often almost impossible to remove.
Most orchid roots are of the epiphytic type, meaning they grow attached to other surfaces--often trees--and absorb moisture from the air and the bark surface. There are two parts of an orchid root: the outer covering, called the velamen, and the tough inner core or cortex.
The outer velamen absorbs water, nutrients and oxygen while clinging tightly to its chosen surface. The strong inner cortex carries nutrients for the plant.
Orchid roots adapt in order to maximize effectiveness in absorbing nutrients in the air. For example, some orchid roots grow upward, extending their roots to absorb moisture in the air.
Orchid roots are sensitive to change and grow for their specific environment, so changes to the environment have to be made slowly so the plant can grow a new set of roots.
- The Canadian Orchid Congress
- Different Types of Roots
- The Royal Botanical Gardens
About this Author
Eulalia Palomo has been a freelance writer since 2009, with her work appearing on GardenGuides and eHow. She has studied herbal and alternative medicine and worked as a landscape artist and gardener. Palomo holds a Bachelor of Arts in liberal studies from Boston University.