"Had no idea Mulberry is an excelent firewood"
That reminded me of an email I rec'd a few weeks ago from a friend...I copied portions of it below. Seems Mulberry, 'Chinese Che', and Osage Orange are related. I had given him a hard time about a post he'd written about 'ingesting' a Che and got an explanation. If Mulberry is related to Osage Orange (which also has milky sap and is one of the hottest burning woods)...that would explain its burning characteristics. I saw a Mublerry tree on the farm that was split in a storm last year, I'll check it out and see how it burns. Che
"Cudrania tricuspidata. aka Chinese Che or Mandarin Melon Berry - probably some other monikers, as well. Fruit(or at least the descriptions and photos I've seen) supposedly resembles a small Osage Orange, turning red when ripe. Supposedly have a flavor reminiscent of watermelon. Leaves look somewhat like Osage Orange - I'm guessing it would be a decent ornamental tree - probably has good yellow fall color. They're routinely grafted on Osage Orange understocks; from what I understand, on their own roots, they're extremely thorny and sucker like crazy.
I also attempted grafts of Che (fruit) onto mulberry, and they leafed out but then died back. Mulberry, Che, and Osage Orange are all members of the same family, but I guess Che and mulberry are not graft compatible."