This one is related to macranthum and patens. The flowers are bigger than either of the former and are non-resupinate. This really is as much as they open, and they smell like grape koolaid.
The largest dimension is about 4cm. This is bizarre flower that opens and curls on itself. Unfortunately the flowers only last for a few days (same for other species in this subgenus). But they make up for it by producing lots of flowers up and down the rhizomes over about a month.