That's fascinating, wwh! And, oh, how true! We have many beeches that grow abundantly near water here in Virginia, and it is true that they do not grow right upon each other. I had assumed that the young beeches wouldn't be able to grow because the older, larger trees blocked the sunlight. This hormone information is news to me.

Here's a bit of beech trivia:

If you were to come across a very young beech in the winter--one so small that it had not developed the quite distinctive bark of the beech--you could immediately identify it by its bud. The bud on the beech looks just like a tiny cigar. And the mnemonic you use to recognize this bud is:

"Smoking on the beach."

It really works. I can spot an infantile beech every time by that cigar-dead-ringer bud. A doctoral candidate in dendrology taught me this bit of beech trivia.