This is a species from Laos and Thailand.
I got this in bud a few weeks ago, so I take no credit, but it's been quite interesting to watch the buds to develop.
At some point, they looked like they were aborting with very ambiguous (but natural, now I know) color of the buds.
The intense hot orange color ( of the buds right before they opened and the flowers themselves) refused to be captured on my camera.
Such tiny little thing but relatively huge flowers.
Anyone who grows this one is welcome to share the know-hows.
Interesting fact: the flowers close (not all the way) at night and open wide during the day time.