What if your knowledge of plants (and fruits and berries) will (painfully) make you aware of what you can eat safely (or mixing with other ingredients to make it lesser poisoning) the herbs that you found ?

Poisoning could range from getting sick and vomiting for 10 minutes to temporary stat/skill decrease or worst.

By experiencing the foraging you will learn what it can do for you (and it is character based, it doesn't count if you read on a wiki page, you need to experience it first hand).