The term Air Plants usually refers to tillandsias which grow on the branches of trees and shrubs, on rocks and cliffs, even in the sand on beaches or in deserts and sometimes on other plants such as cacti. Tillandsia (till-AND-see-uh) is the largest genus in the bromeliad family, with 550 known species and new ones described every year. Many of these species have silver or gray leaves, and they have adapted to seasonally dry habitats. Although they do not catch and hold water in reservoirs during the brief rainy seasons they seem to live of the air – hence the term: air plants. The leaves of these tillandsias are coated with specialized trichome scales which can absorb molecules of water and minerals from the air. Some tillandsias have twisted, undulating or curled leaves. Others have succulent leaves, or form hollow, bulbous structures at the their bases. Still others develop long, vine-like stems.
Close up of tillandsia trichomes
Atmospheric tillandsias easily adapt to indoor culture, grown in the window or under fluorescent lights, mounted on cork bark or other rough, wood substrate. Since most homes cannot match the much needed humidity of their native habitats, tillandsias need to be soaked in water for 40 to 60 minutes, weekly to bi-weekly.