I recently Found this mushroom growing the bottom of a peach tree in an irrigated lot. I live in Tempe Arizona, and I have not seen the like to date, not that I have been into mushrooms, and on the lookout, for long. definitely an inch or more thick where it attaches to the tree.
This one is a not centered picture of the underside. Sorry its not the most clear picture but i think it gets the point across.