Strange tree

I was given this little tree by a friend who had succumbed to the wiles of a mail order garden catalog (short one to the left) Beguiled by the wonderful photos of trees and plants she ordered. She brought me a 3 inch stick and told me it was a fast growing tree that would have glorious purple flowers. I dutifully stuck it in a pot and put it outside. I know most pretty and lush plants are not made for the desert southwest. I watered it and ignored it. It grew to about 18 inches that first year and I started to like my stick, but being pragmatic I left it outside all winter and dared it to freeze and die. I wasn't willing to baby it indoors all winter, after all you dont pet wild animals and trees are not for indoors. Lo and behold it only froze back 6 inches and I admired its' tenacity. I gave the tree its' very own spot in the yard last year and it responded by growing several feet AND putting on leaves the size of large dinner platters! I am by now very attached to it. I ended up with a sling shot looking tree because of the freeze the year before it sprouted another stalk. It grew so much I didn't have the heart to lop off the second branch after that much effort on the part of the tree. I was still wondering about the glorious canopy that was supposed to sprout. I only had 2 sticks with leaves. This spring it seems to be sprouting branches. It is going to be fun to watch how it grows. I have never seen anything like it, so if someone knows what it is and where it normally grows, I would LOVE to know. Naturally, my friend has no memory of what she ordered. It only froze back about 3 inches on the top this year so I think it is becoming large and hardy enough. We will see on the water requirements. I am posting photos from the beginning and end of last year and the new buds I just photographed. This thing grows FAST.