I got this from N2TropicAL (thanks, Hayes!). I thought I'd post a few pics and see what you think it might be. First, the pic from Hayes's gallery of the mat where mine came from:
And here's mine:
Pseudostem closeup (top)
Base of the pseudostem:
Got a couple of pups coming along:
It is a pretty vigorous banana. The upright leaves made me think of Musa textilis, but Musa textilis has narrower leaves and no wax on the pseudostem. It is from Laos, and who knows where else. Any ideas?