Skyrim had that mechanic. You could eat ingredients for potions and if you had a duplicate it would tell you the effects, and the next time you found the ingredient again you would know what it was.
Good that they also have potions, so that no poison in the world is strong enough to kill you in Skyrim (or is there one?)
There is one raw ingredient in Skyrim which will kill the player. But it can't be found in the wild. It's given to you for a Dark Brotherhood quest. But you don't have to use it in the quest. Can keep it for later use.