This hasn't bloomed for me since I got it about six (?) years ago. It's
now got three spikes (thank you, greenhouse!) of two smallish flowers
each and a very, very faint smell (yuk). It's B.trigonosepalum x
B.nabawanense. Three points if you recognize the reference in the name.

Now that I've finally looked up the parentage, I need to get hold of
them - they're both quite lovely.