EPIPHYTES
Epiphytes are defined as "plants living on other plants, deriving support but not nutrients from their host trees". They reach their greatest abundance and diversity in tropical montane cloud forests, but are also an intriguing and important presence in lowland tropical wet forests.

As with some other rain forest plants, epiphytes tend to occur in different strata of the forest. Canopy epiphytes are exposed to the sun, wind, and occasional dry periods. As a result, they show many of the same adaptations as desert species: foliage that is either thick and leathery or very narrow to prevent dehydration, and extremely efficient ways of absorbing and storing water. In contrast, epiphytes that live in the subcanopy have to contend with low light and permanently damp conditions. Many have thin leaves, "drip tips", and velvety textures which increase the surface area and thus the light-gathering potential of the leaf.

The substrate for epiphytes may be the rough bark surface, crevices within the bark, moist crown humus lying over large limbs, pockets of arboreal soil, or deserted ant and termite nests. Of special interest are "epiphylls", mosses, liverworts, and algae that grow on the surface of living leaves.

Epiphytes must deal with different life constraints than do terrestrial plants. The host tree may drop its branches or shed bark rapidly. Such events spell doom for most epiphytes, for they are unlikely to survive the fall or the damp, shady conditions of the forest floor.

Another constraint for epiphytes is how to garner and retain nutrients when they have no access to the bank of water and nutrients in the forest floor soil. Many have swollen stems or leaves arranged like funnels to collect water.  They must also be prolific and adaptable in their reproductive strategies. Many reproduce asexually in between sexual reproductive events.