Plants That Grow in Fresh Air

• Orchids are epiphytes that draw their nourishment from the air. Nathan Blaney/Photodisc/Getty Images

  Plants that grow in fresh air live on a host plant, but get all of their nutrients from the air, the rainfall and any naturally generated compost on nearby tree branches. They are called epiphytes, and there are more than 30,000 different species worldwide. Most epiphytes are found in the rainforests and cloud forests and might be lichens, ferns, mosses, orchids, bromeliads or cacti.

Orchids

• Orchids are the divas of flowering plants. Their colorful, moth-like and clustered blooms are found in tropical and neotropical forests from low-lying swampy areas like the Florida Everglades to the Himalayan foothills. There are fewer than 20,000 orchids identified with a likely equal number unidentified. Orchids are extremely adaptable and are a favorite plant among horticulturists and in the flower trade. In the wild, their very large roots are well-made for drinking in rain and nutrients. In captivity, they need open, hanging planters or special light potting soil mixes to ensure the roots can breathe. Their numerous microscopic seeds are easily carried away by the wind and so orchids propagate easily if their habitat is undisturbed. Unfortunately, loss of habitat means there are orchids that will never be identified because they will go extinct. Some favorite orchid varieties are paphiopedilums, vandas, cattleyas and cymbidiums.

Bromeliads

• A small, graceful type of bromeliad, known as tillandsia, is a complete epiphyte. You may have seen them --- little bursts of green spear-like leaves clinging to branches or tucked into forks in a tree. Most people just call them air plants and they are remarkably hardy and need little more than air. The mother plants form pups that will grow to maturity while the cluster of plants is in a large ball shape. The plants can be separated, or left to continue to clump in a denser cluster. Tillandsia are so hardy they can be shipped dry and just spray soaked on arrival to revive them. One of the most common tillandsia plants, Spanish moss, is found draped all over trees in the southeastern U.S. in long grey-green beards. It isn't a parasite, but the spongy moss can hold enough water to break a branch.

Cacti

• The cacti that are epiphytes have different needs than their relatives in desert landscapes. They don't look or act like the version of a cactus that first springs to mind. But there are cactus air plants, and they have no stickers or spines. They can produce lots of bright flowers and grow long segmented leaves that are designed not to hold water but to absorb sunlight. Most tropical cacti are epiphytes, so you will find them in the tree canopy, high above the forest floor, where they can get enough daily sunlight to survive. One epiphytic cactus most people are familiar with is the Christmas cactus. The plant is often given as a gift during the holidays because it is a winter bloomer and will produce bright red-orange flowers against vivid green segmented leaves. If the Christmas cactus is overwatered, the flowers will drop off the plant after blooming.