"Up the airy mountain, down the rushy glen,
we daren't go a hunting for fear of little men.
Wee folk, good folk trooping all together.
Green jacket, red cap and white owl's feather.
By the craggy hillside and through the mosses bare,
they've planted thorntrees for pleasure here and there.
If anyone's so daring as to dig them up in spite,
he'll find the sharpest thorns in his bed at night."

This is based on a poem by William Allingham. He had his folklore "down." The same warning about damaging thorn trees was given to me 25 years ago by a lovely red-haired Irish lass. Check here for the complete original text

Slainte,

J.