Since Ursula is out on this one let me expand on my guesses. All of the orchids we are discussing here are in the Oncidium alliance so they have similar growing conditions. Here is a look at one of my Degarmoara orchids:
It has a different shape than the Miltassia. The Bollopetalum is closely related to the Zygopetalum and looks like this:
So, I think I am close and if you look up Oncidium culture, you should be ready to go.
Jim