No sphagnum, no bag, just a bit of humidity
For many orchids, dry is better. The roots develop in pursuit of moisture. Dendrobiums and Laelias do best in large rock pieces that hold very little water.
Cyrtochilum serratum grows in western Ecuador in montain cloud forests at high altitudes. It is cool to cold growing and has a very long, spectacular spike.
The genus Cyrtochilum contains 50 species of terrestrials separated from Oncidium for technical reasons. They grow at high elevations in the Andes from Venezuela, Colombia and south to Ecuador and Peru. Keep cool and moist.
I got this as a gift; a pair of rootless backbulbs. Very collectable and a perfect example of a plant I couldn't afford to get any other way. It has now progressed through the sprouting and transition phase. It has two new pseudobulbs, the original pseudobulbs have been removed and I will look for a spike next year.
TRIBE: Maxillareae SUBTRIBE: Oncidiinae