I love books on herbs and finding natural foods in the wild, but what few folks realize is that these things can be fatal (fatal herbal poisoning, usually accidental, were alas common when we worked in Africa and folks tended to self treat).
I ran into this one very funny one from the University of Bath:
Say it with poisonThu, 25 Apr 2013
In this lecture, Mr Russell Bowes, a freelance garden historian, will be sharing mysterious tales of how people have died in the garden, and how you can protect yourself against herbaceous murderers.
Download MP3 [20MB]
and, of course, the book "wicked plants" is another great book on the bad news of what grows around you innocently. Luckily I can read it at Scribd, but an interview by the author is here:
or this longer talk at googletalks: