Tropicals & Tender Perennials: What kind of begonia is this?, 0 by Ispahan

Ispahan wrote:
Hey all:

A little less than a year ago, I happened upon a miserable, lanky-looking rhizomatous begonia trying to grow in a dank, sunless hallway at a local university. The plant's only light source was the occasional fluorescent light fixture suspended approximately 15 feet above the plant. What few leaves it had left were an intriguing iridescent green/blue/black, and I think this unusual though subtle show of colors was what inspired me to quietly pluck off a leaf and take it home with me. Needless to say, the leaf quickly rooted and pupped for me, and it has grown into the plant you see in the image below, now spilling out of an 8 inch clay azalea pot. The plant itself is about 6-9 inches tall and about 15 inches wide. While the plant is robust, healthy and beautiful, you can see that it no longer has any trace of that unusual dark iridescence it once had (probably due to lack of light) and now has markings typical of what seem to be called "eyelash" begonias. It has not yet flowered for me. Can anyone tell me if it is a species or a hybrid cultivar? If so, which one? Thanks in advance for any help or comments.