Neobathiea grandidieriana

Also know as Neobathiae filicornu. I grow it cool in the winter with reduced watering. The flowers open green and than lighten up in after a couple of days.

 

Thanks, folks.
MrB, it has been a reliable bloomer for me too.
Alexey, I'm not sure how long they last. Last year the first two of my clones bloomed and almost immediately set a capsule (not of my doing). The third I pollinated so never took note of the time. Beyond one year, my memory isn't so good. Perhaps others can answer the timing factor.

 

I brought this in last night to check for fragrance (none at the time) and decided to take a better close-up. I also noted that the first flower was already fading, but will wait and see if it was pollinated or not. This grows with a theoretical minimum 50F night. But with pilot issues it occasionally goes below that. I keep it fairly dry in the winter. Perhaps next winter I will try one with a warmer winter (56 is my warmest).