Do plants think?

It is commonly assumed that plants can't think because they have no brains. But I found a couple of examples proving that plants may, indeed, be thinking:

A tree on crack:

There was a tree growing out of the side of a rock from a tiny crack. About 3 or 4 feet above the crack there was another crack. The tree grew a root straight out at a 90-degree angle at the exact height of the second crack - a single thick root aiming directly for that crack. There is no way it was a chance, trial and error thing - it took a lot of juice to grow that root; it was a life & death decision for the tree - it had to be right on the first try! The crack not only provided the nutrients, but also enabled the tree to grab onto the rock, so it wouldn't fall off.

Plants have good taste in books:

There was a study done in England: plants were read to, and their growth was measured. All the plants that were read to grew bigger and faster than the bored control group. But guess which plant grew the best? The one that was read Darwin's Origins of Species.