I love growing the peculiar as well as the beautiful, and its really great when both qualities can be found in the same plant. Not having a greenhouse makes it a challenge to grow Sobralias, as most of them are pretty big plants. Nonetheless I can't resist trying. I picked up this Sobralia, S. powellii, at one of the GNYOS shows some years ago. Luckily it has survived, and this winter it got to spend time in my classroom in bright light (alas, no sun ever enters my classroom windows, but they are really large windows) supplemented by fluorescent lights suspended from the ceiling. It has done well for a non-greenhouse orchid, and is shown with its second flower in a week. The white flower is exquisitely shaped, about 4-5 inches in diameter, and wonderfully scented. But, in the manner of nearly all of its kin, it is here today, gone tommorrow. I attempted to pollinate it, we'll see if it sets seed later on. More flowers will likely emerge from the sheath that terminates the growth that bears this flower.
Sobralias seem to adapt to a terrestrial mix (bark or peat based) with liberal amounts of perlite for aeration. Roots can rot easily, and this is the biggest danger to these plants. They also can grow in sphagnum moss, in fact newly imported plants often do better if they are planted in loosely packed sphagnum to regrow roots. However I summer my plants outdoors where excessive rainfall can make sphagnum a dangerous medium for sensitive roots. So if planted in moss, watering frequency needs to be controlled so that the moss dries out a bit between waterings.