I got a note from Chiqui.
Had to try out your backbulb theory and so I divided a Dancing Ladies oncidum that didn't seem to be doing very well. I decided to mount it since it is easier to just water every day and not have to figure out if the plant is wet or not. Anyway, had about four rootless, leaveless backbulbs and mounted 2 in one mount and 2 in another just to see what would happen.
Well, that was last December 6th and here they are two months later and they have both sprouted! Not only that, but I divided the orginal plant and mounted one and kept the original one in the pot and both are about to bloom.
Good job, Chiqui!
Dancing Ladies is a general term for a group of species and hybrids that have big spikes and lots of flowers. Each of the flowers looks like a lady in a full skirt and a big comb in her hair. They are very beautiful and most last in bloom for quite a long time. The plants can be a bit on the large size for a windowsill but worth adding to your collection. They do well indoors and look good even when not in bloom.