I got this 'T.R. Hovey' papaya as a tissue culture plug over a year ago (thanks, Tom!). It sits on my desk right next to a window and gets direct light in the early morning and then indirect light the rest of the day. I water it regularly and fertilize it occasionally.
When I came in this morning, the flower petals had curled backward exposing the unique, antler-like structure that I think is the stigma (see it close up). I don't see any stamens (the male, pollen-bearing structures). My pictures in my Botany Illustrated book makes me think it's a unisexual flower, but then I'm not sure how it could bear fruit. Tom says it's a bisexual flower, which would make sense if it's able to produce fruit on its own.
Secretly, I think Tom envies my papaya. He left his papaya outside and it's looking somewhat sad right now, since the colder winter temps caused his plant to drop a lot of its leaves. Mine not only has flowers, but also plenty of leaves. For once I have out-gardened Tom!