Catasetum atratum Lindl., Edwards's Bot. Reg. 24(Misc.): 61 (1838)
This one is from Brazil, São Paulo, Santa Catarina, Minas Gerais and Rio Grande do Sul States.
It is a epifitic plant. The appearance and forms of the plant are typical of this genus.
It is easy, just regular Catasetum culture.
One curiosity, this is one of the species that can easily give male and female flowers in the same inflorescence. Never did it here, sadly... perhaps it needs to be bigger.
The photos should have been taken some days ago, the flowers were already dying.