While I was in Beijing my friend L gave me two decks of cards. One has these — leaves of various places — printed on them, while the other has pictures of various villages that produce puerh. I find it interesting how the ace of spades is from Longpa, while my favourite, Yiwu Gaoshan, is only a mere ace of clubs. The other two are Yibang (ace of hearts) and Yiwu Guafeng zhai (ace of diamonds).
There’s the rest of the deck too, all with leaves from different places. You can see that someone spent a lot of time collecting all this, documenting them, and then putting them to good use. There’s a scale next to most of the cards too — you can see faint lines here in the scan where they say “5” “10” etc. I think that’s cm, to give you a sense of how small (or large) the leaves are.
It’s not necessarily of any real use per se, but it’s definitely interesting.