What Purpose Do Orchids’ Aerial Roots Serve?

Aerial roots, a type of orchid, are a normal part of orchid anatomy, particularly for epiphytic orchids like Phalaenopsis and Dendrobiums. These roots are coated with a spongy tissue called velamen, which holds in water and prevents the plants from becoming too dry. They are essential for stability, as they signal the safe sending out of a flower spike.

Aerial roots absorb atmospheric water, such as rain, mist, and dew, and provide structure to the roots. They also produce a sticky substance that allows them to adhere when they come into contact with a surface. Absorptive trichomes are conspicuous structures that assist in efficient uptake of water and nutrients.

Exposed orchid roots are a normal feature of these uniquely beautiful plants, and tending to them is an important aspect of orchid care. Aerial roots are most likely to occur in epiphytes species, which grow on other plants, such as branches or trunks of trees. The water is absorbed by imbibition into a biological porous material, the velamen radicum, which envelops the aerial root and comprises one or two to several layers.

Orchids use their roots to absorb nutrients from the air, absorbing moisture and obtaining carbon dioxide they need to thrive. Aerial roots perform important functions for the orchid, such as aiding in photosynthesis, absorbing water, and maintaining the plant above the surface of the soil on which it grows. If the velamen is modified by mechanical injury or after the root becomes attached to a solid substratum, the root may serve as an absorbing organ.

In summary, aerial roots are a crucial part of orchid anatomy, providing stability, structure, and water absorption. Proper care and maintenance of these roots are essential for the growth and health of these beautiful plants.