In a SHTF situation, food will be treated as gold.
Those who will survive will be both prepared and creative enough to have other food sources outside the conventional ones, one of them are wild plants.
Crazy enough, some wild plants are really edible but there are a lot of poisonous wild plants too. Hemlock is often mistaken for wild carrot, which leads to accidental poisoning. So how do we know the difference between the good and the poisonous if they look so similar?
The first option is to familiarize yourself with their leaf, stem and root structures. Knowing the edible plants thoroughly will prevent you from consuming poisonous plants accidentally. Some people will want to know the taste of the edible plants so that they remember it when time comes.
The second option is more risky. it involves having to figure it out. Separating the plant piece by piece, then testing each part on your skin, smelling it if it is acidic (acidic is bad), licking it and trying to chew on it. Here are the instructions should you need them.
Wild mushrooms are highly discouraged to be eaten.
This is a great video showing the edible wild plants: