Symplocarpus foetidus
arcangelo wessells (Sun, 07 Apr 2013 21:46:49 PDT)

Arum rupicola var. virescens also generates heat when it blooms. They bloom in the evening, usually around the end of april, with a nice manure smell and when you put your nose up to them a shocking burst of warmth.
I couldn't find a photo of my plants, but here is one off the web:

http://hillkeep.ca/images/…

Hi Ellen-

Another neat fact about them is that they will generate their own heat to
push up through the snow.  They are native here in IL too.  I was too busy
to see if this fact is true- we had late enough snow.