Fredclarkeara = (Catasetum x Clowesia x Mormodes). Fdk. After Dark ‘Black Pearl’ is one of the few truly black orchids in existence.
This stunning orchid belongs to Lesley Newton. She grows this from a flask seedling. It seems not very hard to grow it if you get the key points. She uses normal potting mix and she suggests not to dry them off for as long as Fred Clark stated.
For more details about how to grow this kind of orchid, I found one video from Youtube which may be helpful.