http://forums.gardenweb.com/forums/load/begonia/msg0715373110244.html?6

anyway, i was grooming and watering, when i was startled by an offshoot with little pink/white pedals, and a bright yellow fuzzy center.
I happen to be quite suprised, i had believed the rex to be a simply non flowering breed. i will post photos soon, most likely within the next two days.

Andy

Serratipetala is a shrub species from New Guinea and can grow quite nice if given plenty of humidity (mine is like a weed in an old aquarium). The growers that provide these rexes to the big 3 box stores usually label (in this case mis-label) all of these begonias as Rex Serratipetala which can be very aggravating. I think they must've had a million of those tags printed and won't change them anytime soon.

and hcmcdole, i believe you are correct with the mis-labeling of the rex, the only thing i am certain of is that it's a rex.
And i have this great little unexpected flower.

i wish my camera could capture how the center (pollen perhaps) looks like four long curly yellow strands, not just a blob of pollen.
also, the flower opens during the day and begins to close as it gets colder, until it's practically closed, just to spring back open when it gets warm / light.

i may sound like a complete novice to gardening, because i am. and this is my first houseplant. But putting it in my very small bathroom, with a frosted west facing window seems to work.

thanks for the input , and i hope the pics help.