There are lots of rhymes for teaching children about the various trees, etc.,
The Elder tree is the Bour tree in Scots,
Bour tree, bour tree
Crookit wrung,
Flower and fruit baith sae sweet,
Ne'er trust a stick beneath your feet.
The Elder often grows crookit, it creates bowers (the origin of the name) and the branches are kind of brittle and climbing one often breaks it with a crack.
Folks had to 'ask the hag' in the tree (the jelly ear fungus grows widely on Elders, so the tree has ears to listen) before they took flowers or fruit or a branch or so for kindling.
Kind of superstition, if you fell, well you hadn't asked courteously enough.
But in comes a faith that cannot thole anything that smacks of 'paganism', and the tree that was once seen as a virtual pharmacopeia of herbal medicine becomes an evil thing.
The rhyme changes and the tree becomes the tree used for the crucifixion....except the Elder doesn't grow in the middle east and the ears weren't those of the ones cut off the folks who didn't follow the same faith, and were nailed to the tree, either.
The rhyme changes and it becomes,
Bourtree, bourtree, crooked rung,
Never straight, and never strong;
Ever bush and never tree,
Since our Lord was nailed to ye!
The very useful fomes fomentaria fungus, the stuff used to make clothing pieces, as well as being an excellent fire carrying tinder, kind of gets the same treatment.
If you char the fungus, it'll take a spark even from quartz.
Thing is though, if you get a glowing ember into the centre of the underside of the fomes, you can literally carry fire in it. I've had one quietly glowing away and slowly burning out for nearly four hours, and you can pick it up in your hands to carry it safely.
But it looks like a horse's hoof growing out from the trees. Now that didn't suit a faith that thought anything of that ilk to be pagan and superstitious, so it becomes the Devil's toenail/hoofnail and something to be avoided instead of thought well of.
After all, everyone knows toadstools and fungus are poisonous and pagan, don't they ?
As cheugh as Auld Nick who burns forever,
Roast it black and they'll burn thegither.
Aye, indeed, nowt so queer as folks, or ancient propaganda.
M