There are at least 202 species in this epiphytic, cloud forest, cool growing genus found from Costa Rica to Peru with the highest concentration in the high Andes of Colombia. They prove to be one of the most difficult orchids to maintain for any length of time. They are delicate, dwarf epiphytes without psuedobulbs, made up of clustered or distant, speedily deciduous, leaves ,which, from the axils arise a slender, few flowered inflorescence. They need damp cloud-forest conditions with deep shade, cool temperatures and ample air circulation. The cloud forest areas not only are damp but a permanent fog blankets the ground and light is rarely high, as it is difficult to even see 10' on a 'clear day'. They are one of the wettest orchids that you can grow and as such need to be misted constantly and watered regularly.
Source: Jay Phal
http://www.orchidspecies.com/i...
There are a few that are slightly cool intermediate, but probably difficult to find.