OK, I think we need to look more closely at the flower seed pods. On each flowering stem there appears to be three flowers, male are the simple ones with the female flowers having inflated pods and smaller petals below the pods.
I've looked closely at the drawings, those of Begonia hirtella look a good match. Note how there is one 'wing' a little larger than the others on the seed pod, but the larger wing isn't much bigger.
http://plantgenera.org/illustr...
Now, look at the seed pods on drawings of Begonia hirsuta, one wing is much longer and narrower than the others, which don't look to be very big at all and look to be barely existing.
http://www.plantillustrations....
