The thick sponge-like covering of the roots of epiphytic orchids which helps prevent water loss and aids in absorption.

a water-retaining outer layer of the aerial roots of some epiphytes, especially orchids.

The thick corky layer of cells covering the roots of epiphytic orchids. It serves to protect the roots and also as a rapid water absorption device.

Tissue that covers aerial roots of the ephifytic orchids which absorbs water and prevents excessive evaporation from the root tissue

Special adaptations of roots are found among epiphytic or semi-epiphytic plants such as Orchid sp. and Clivia. Velamen is a spongy, multiple epidermis that covers the roots of some of these plants.