SK 2952 08 September 2021: 6 very high res. images.
Location: Surkhet, West Nepal
Altitude: 652m.
Date: 11 August 2021
Habit : Wild
Colocasia fallax Schott ??
… may be able to confirm or otherwise pl.
This looks very unusual to me, though it is hard to judge colour in the lighting (camera flash?).
The spathe and spadix have a general shape similar to what I have seen in certain wild C. esculenta populations (with very long upper spathe), but your spathe appears almost translucent and white… we can see the upper spadix through the spathe membrane it seem.
The bade is also peculiar, narrowing towards the rear with shallow sinus, and with few lateral ribs, but the lamina is broadly similar to most Colocasia spp.
I suspect this is something in the group of species that are close to C. esculenta in evolutionary terms, but would need to look at the chloroplast sequence to place it in that group. Does this plant have stolons, or side corms, or erect stems with buds that form new stems directly (this last form of vegetative growth may be hard to confirm if the buds are shy sprouting).
Do you have any photos in natural daylight?
Found your daylight image! The spathe is unusually pale for Colocasia, but overall inflorescence is surely Colocasia sp. The long upper spathe also broadens in the closed distal portion, before narrowing to the tip. That is also very peculiar!
Note also that the lower spathe and peduncle may be close to circular in cross-section, with an erect peduncle at the time of floral maturity, not reflexing towards the ground. It would be good if this peduncle behaviour can be confirmed on more than one plant.
Unfortunately only these images.
I came across an image from a book published by the Government of Nepal which looks like it matches my post.
The book photo shows a shallow sinus, but it has a distinct cleft, and the upper spathe is a relatively strong yellow (even taking into account that the colour may have changed as a result of image processing).