any plant that grows upon or is in some manner attached to another plant or object merely for physical support. Epiphytes are primarily tropical in distribution and are often known as air plants because they have no attachment to the ground or other obvious nutrient source. They obtain water and minerals from rain and also from debris that collects on the supporting plants. Orchids, ferns, and members of the pineapple family (Bromelialacae) are common tropical epiphytes. Lichens (lichen), mosses (moss), liverworts (liverwort), and algae are epiphytes of temperate regions. Mistletoes (mistletoe), which are partly parasitic on their host plants, are sometimes considered to be epiphytes.