Though I dont know the technical answer, I can tell you what I found once.
Father in law had a plant that was growing under his foundation and outward at an angle under his overhang. The thing sprouted up from "nowhere" and was growing like a weed.
Long story short, he was going to let it grow to "see what happened" but he told me about it. When I went over to see it, I recognized it as one of these trees. He immediately did a laugh and an "omg" at the same time realizing that a tree might cause more damge than a large 'weed".
None the less, the tree was probably 8, 10 feet tall. I took a round point shovel, dug once into the ground and POP. The tree came right out. I had the backhoe with me and was prepared to put a strap around tree so we could pull it up/out but it turned out to be quite easy. also, as I recall, the rootball was rather small.
We transplanted the tree to see what would happen, several weeks later, the wifes cousin was next door at his fathers and we were over visiting. He happend to ask if we noticed the huge WEED we had growing over on our hill /forums/images/graemlins/confused.gif Seems it runs in the family blood.
We had a good laugh that everyone thinks our poor tree (that we are proudly trying to keep alive) is a large weed.
I dont have a digitial type camera, but I'll try to get some pics of the various trees we have (including the weed if it's still standing) Oh, and none of them have leaves now, so they look somewhat anemic.
Bad part is, won't have film back for several days.
Richard