I've been away two weeks on vacation and was interested to see what turned up on this thread. A common theme that I mentioned before is a taboo about a woman placing her affection on a young green-growing tree. I'm sure you've heard it in "On Top of Old Smokey":

Come all you young maidens
And listen to me
Never place your affections
On a green-growin' tree
For the leaves they will wither
And the roots they will die
You'll all be forsaken
And never know why

Does anyone know the origin of this idea? It makes me wonder if the first verse to "Young, But daily growing" or "The Trees They do Grow High"