Hi Frank!
I bred a non-tessera to a tessera and got all tesseras. You can see the thread here:
http://www.cornsnakes.com/forums/sho...d.php?t=147160
It is quite likely that the male is a homo, or super tessera. I sold him back to Don @ SMR where I originally got him from and he will continue to prove out his genes. In conversations with Don, he states that it is rare, but there are homo, or super, tesseras.
-Tonya