Epiphytes, how many types are there? No one really knows. In one research project, they found over 2100 species in just 500 square meter, about the size of a very small front yard! And epiphytes are not just in the tropics, but every where! There will probably be new types of epiphytes discovered for decades to come!
An epiphyte is any plant that does not live in the soil, have true root systems, and frequently lives on another plant providing no benefit but causing no harm. This differentiates them from Symbiotic plants or parasitic ones. Epiphytes are often referred to as Air Plants, but this is incorrect as there are aquatic epiphytes, Air plants are arboreal or terrestrial epiphytes..
Most people think of epiphytes as being those beautiful orchids or bromilliads that are commonly fount in tropical rain forests. They are there in their thousands if not millions, often forming the canopy that protects the plants beneath them. Few people realise that some mosses are epiphytes and so is "Spanish Moss". As any horticulturist can tell you, epiphytes do not have to grown on a living plant. Orchids and bromilliads as well as climbing philodendrons can all grow on rocks as well as dead plants.
Aquatic epiphytes are found in both fresh water and saltwater. They can grow on grasses and other aquatic plants, as well as sunken logs, rocks, coral, and even sea turtles and whales.
Epiphytes are really diverse. All they need is something to hold them up, the right nutrients, and they take off! There are the orchids and bromilliads mentioned earlier as well as Liana epiphytes (climbing vines), mosses, lichens, frens and even some succulent (cacti) epiphytes.
How do the different types of epiphytes spread? Mainly through wind and air, but also via insects, bats and even lizards. Some produce seeds that stick to either fur or feathers, and then fall off when wet or dry. Many produce edible fruit, get eaten by various creatures and then the seeds pass through the digestive tract and come out fertile, getting spread and fertilized! Aquatic epiphytes are spread by rivers and ocean currents, sometimes by fish and aquatic insects and even the occasional wading bird or wandering turtle! Epiphytes are some of the most adaptable and varied flora found around the world.
Some have been found to contain medicinal properties and many are edible (vanilla is from an orchid and pineapples are bromilliads). They can grow without soil, so may be a valuable source of food in the future. Epiphytes may be the future!