This time I was looking around for more trees around the fence. I found this Maple growing under a shrub. It had been protected from the mower for a long while, and is probably several years old. I trimmed it back a bit, and it had a nice shape, like a matured little tree.
After digging it up. I can see why maples are a used a lot bonsai. They have a mesh of tiny roots:
And transplanting it to a container for recovery:
I gave it a little superthrive (plant hormones). After it bounces back, I will trim it back a little more and put it in a smaller pot. I'd like to try an off-centered style for the growth.