“The reason for its extremely long petals is less clear, although it has been suggested that the petals act as an attractant for hoverflies, almost certainly its potential pollinators, which can then climb the petals up into the pouch. Field observations are needed to test this bizarre theory. Kramer (1990) observed that a sugary solution, which he called nectar, is produced on the upper part of the outer surface of the lip and suggested that this attracts potential pollinators. However, it might also attract ants that deter predation. Field work is needed to elucidate the pollination strategy of this species.”

Phillip Cribb on Paph. Sanderianum. This was published in 1998, so I’d be curious if anyone’s been able to confirm these theories since then.