Simply labeled as "Unknown A".  It produces multiple tubers, grows easily but has yet to produce an inflorescence...  any idea as to which Amorphophallus it is?

...and now this was ID'ed as probably Amorphophallus asterostigmatus (thanks Scott).  I believe that's correct because I did have A. asterostigmatus and the petiole on this does look like the small length of petiole visible on some of these photos:

http://www.kallus.com/aroids/amorphophallus/asterostigmatus/index.htm