For those who are interested in such things, here's a link to an article on the earliest known fossils of trees:
http://www.nature.com/news/2007/070416/full/070416-10.html
They were long skinny things with branches all at the top - would have looked a bit like palm trees - and they grew about 360 million years ago last Thursday.
That's a neat article... I've seen that stump and touched it! I'm doing my MS degree at Binghamton, and I've taken a few classes with Prof. Stein -- quirky guy, but an absolute genius.