My part time job is in a nursery, and this time of year we sell Christmas trees.
One of the species we sell is a Scotch Pine. This family was choosing a tree, and I held it up and turned it so they could see it all the way around. The daughter was about eight or ten, and she said they had a skirt for it.

I told her "It's a Scotch Pine, therefore it has a kilt." Luckily for me, the father got the joke.