No soil tropical plants are commonly called air plants and they really can survive without soil to grow in. Also known as Grey Tillandsias, air plants have furry scales on their foliage, which collect water out of the humid air, and they obtain nutrients from airborne dust. Leaves surrounding flowers may change colors, but the actual blooms last only a few days. The most widespread variety is Spanish moss (T. useoides), but other less known varieties are available as well.
T. caput-medusae is also known as octopus plant or Medusa's head. It has an exotic appearance with thick, twisted leaves originating from a bulbous rosette base, which produces showy mauve bloom spikes and blue flowers. Its foliage can grow up to 10 inches long and is covered in thin gray hairs.
T. ionantha is a small (under 2 inches tall) stemless plant with silvery, arching foliage formed from a compact rosette. In the wild, it forms clumps, often large enough to encircle a tree branch. As the stalkless violet flowers appear, the entire plant turns fiery crimson when grown in bright light.
T. juncea has long, rush-like foliage that spreads outward, with a single flower stalk, often carmine in color, and large multiple blooms of royal purple well above the heart of the plant. This species can be mounted almost anywhere, including upside down.
The 1/2-inch cherry red flowers of T. albertina bloom up to a week. The plant can grow up to 3 inches in both height and diameter, with foliage that fans out two-dimensionally.