I learned about both topics, yesterday at the Mycological Society of San Francisco's Fungus Fair. (Robb went cycling. He wasn't interested in attending lectures, because sitting for any length of time still causes him significant discomfort.)
At this point I'm much more comfortable with the idea of collecting mushrooms for my dye pot than my stew pot. The descriptions of mushroom poisoning were truly horrendous. Basically, the toxins affect your organs so that on the most basic cellular level, halting their necessary function of cell-replication, and killing you via organ failure.
If you are a very lucky victim of mushroom poisoning, you will wish you were dead.
If you are a lucky victim of mushroom poisoning, you will need emergency organ transplants.
If you are unlucky, you will slowly die of organ failure. And there is no known antidote for this form of poisoning.
I'll stick to photography, for the moment. Photography, and pondering dye projects.
How about those sample cards? All of these fibers were dyed with simple techniques, using non-toxic dyeing materials. In many cases, "natural" dyes are quite harmless, but the mordants (chemicals that help the dyes "bite" into the fibers) are very dangerous to humans and the environment. The women who developed these techniques have opted to only work with iron and alum as their mordants.
Interestingly, they have found (despite extensive international research) no records of any kind of mushrooms being used as traditional dye materials. Lichens have been used for millennia, but the use of mushrooms as a dye-source seems to have been originated in Northern California in the 1970's.
Dorothy Beebee is one of the originators of this technique, and co-author of the major texts on the subject. (And who is that smiling brunette holding the camera in the front row?)
Now, I just need to figure out where I can legally collect mushrooms in Northern California. This is trickier than it sounds.