There is nothing like having things pointed out to you first hand...as a child, my Grandfather took me out many times to study the countryside and pointed out what could or could not be eaten and it amazes me that there is so much that we actually can eat....however......illustrations in books can be deceptive and should not be used as definitive proof that something is what it purports to be...after all..if they are wrong and you are paralyzed or worse...who takes the rap?
Suggest that when you have things growing...take them to people who have been country dwellers all their lives...some may know, some may not..but always play safe.
Best wishes, Mike.