In the Middle Ages, a lot of wisdom was stored thanks to the mushrooms. In the Christian monasteries, a good part of the knowledge of that time was collected and preserved in books written with ink of the mushrooms of the genus Coprinus.
Thus, the exquisite shaggy ink cap, lawyer's wig, or shaggy mane, as it is also called Coprinus comatus, was picked and liquidized, turning into black ink.
Coprinus comatus, shaggy ink cap. An exquisite mushroom that turns itself into black ink.
This feature is also found in other taxa of the genus, so it is very possible that in those ancient books there is an interesting spore collection.
More recently, during World War II, some official documents of the Nazis were also written with mushroom ink. Until this was found out, there was no way of intercepting or falsifying them.
It is currently sold dry and in capsules as an aid for benign prostatic hyperplasia. There are several publications that consider it interesting to this end.