Epidendrums are native to the tropics and subtropical regions of the American continents, from North Carolina to Argentina. Their habitat can be epiphytic, terrestrial (such as E. fulgens), or even lithophytic (growing on bare rock, such as E. calanthm and E. saxatile). Many are grown in the Andes, at altitudes between 1,000 and 3,000 m. Their habitats include humid jungles, dry tropical forests, sunny grassy slopes, cool cloud forests, and sandy barrier islands.
Members of this genus can be very aggressive colonizers of disturbed habitat, and many species which were once rare in this genus have become more common as the result of human activities. For example, some of these plants can be found in greater abundance growing terrestrially along road cuts throughout their native ranges as the result of road construction.
Many of these species are relatively easy to grow in rich humus compost with some sand. The plants resemble Dendrobiums in form and habit typically, although they tend to be terrestrial rather than lithophytic and epiphytic, and do better in a humus rich, well aerated substrate.
Most of the high altitude members of this genus from cloud forests defy cultivation outside their habitat, and it is reported that even moving a plant from one location to another on the same host tree in habitat will result in the death of the plant, possibly due to dependency on a specific mycorrhizal fungal symbiont.
They are quite varied in flower size and appearance. They grow in tufts, in racemose inflorescences, sometimes in corymbs or panicles. The apical, lateral or basal flowers are mostly small to medium in size and frequently are not marked by a conspicuous display. The inflorescences are frequently dense. Many species are fragrant. The flowers may be produced only once, or during several years from the same or new inflorescences. The ellipsoidfruits are 3-ribbed capsules.
This genus has the following characteristics:
- a slit rostellum (small extension or little beak to the median stigma lobe), producing a transparent or white thick and adhesive liquid.
- the sometimes fringed lip is adnate to ( = united with) the column (forming a nectary tube (but rarely producing nectar), continuing through the pedicel). The genus Prosthechea was split off because the lip is not completely adnate to the apex of the column.
- the pollinarium contains four pollinia, sometimes two and rarely eight pollinia, and then four very reduced.
- the erect, pendent, or creeping stems are reed-like, simple or branching, or may be pseudobulbs or thickened stems. (The genus Coilostylis, recently split off from Epidendrum, has pseudobulbs, is an artificial genus and deos not stand un to molecular analysis