Because orchids are designed to be an aerial type of plants
roots that never touch the ground for example orchids
Plants roots that are above ground are called aerial roots. Examples are some types of orchids, mangroves, and banyon trees.
Physical support is a primary function of plant roots, and aerial roots are no exception. Climbing orchids, such as vanilla (Vanilla planifolia), use adventitious.
aerial prop roots
orchids
Roots on the upper parts of the plant are called adventitious roots. They are not real roots per se. In some plants, their role is to provide extra support to the plant, for example, maize. In other plants like orchids, the aerial roots function to attach the plant to a surface as well as absorb moisture from the air for the water requirement of the plant.
In tropical rain forest,certain orchids grow high up in the trees,dangling their roots in the air
answers; orchids bromeliads tillansia stag-horn fern spanish moss pand
Among others: Orchids - Phalaenopsis, Vanda, Dendrobium, Catlleya Bromeliads Tillansia Stag-horn fern and Spanish Moss
ambot
The roots that take moisture out of the air for survival are called aerial roots. The roots are usually found above the ground so as to be able to perform their function.
Aerial roots