I've always seen Spearmint.  In fact, I grow some on the deck.  Man does it take over!  Not a bad thing.   <img src="http://www.traveltalkonline.com/forums/images/graemlins/Grin.gif" alt="" />
 <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" />  Contessa