Herblore. No, this isn't about pot. Well, maybe.

Herb Lore

The various ecosystems of the planet Earth are ripe with plant life. According to Wikipedia, depending when you visit the site, there are somewhere between 7 and 3,100,042,069 species within the Kingdom Plantae. At least one of which (and seemingly the most important) is Marijuana. The same article informs me that neither Hot Pockets nor money grow on trees. Further research even implies that Hot Pockets aren't even organic. But that can wait for another day.

Plants. Great. Boring. Plants take energy directly from the sun, and turn it into chemical energy that can be processed by the rest of the living organisms on the planet. We, of the Animalia Kingdom survive as parasites on these plants. Both directly and indirectly. As omnivores not only consume plants and their products for nutrition, but we also consumer herbivores. A meal of a hamburger and fries usually consists of beef(or a patty described as meat), which originally came from a living animal that was raised on plants. If it is beef, then the cows were fed on grass, and in this modern age fattened up on Maize(corn). The buns are probably wheat based. The fries are usually some form of potatoes, and the cooking oil that the fries are cooked in is usually squeezed from 'vegetables'. This isn't even to touch on the condiments and other toppings, as well as the paper which the meal was wrapped and delivered.

The fuel that powered the vehicle to get you to Burger King comes from fossil fuels that were plants/animals tens of millions of years ago. The wood that forms the table? And so forth all the way down the line. Then there all the plants that can be used in remedies, to lower fever and calm upset stomaches. We use them for everything. Plants are King.

How many people do you know who can tell a potato from a carrot when it's still in the ground? For you of the 420 variety, Cannabis from Hemp. And the rest of us, Poison Ivy from just about every other tiny ground-cover weed on the floor of the forest.

Human beings started out as nomadic hunters and gathers. Mostly we survived on meat, but we used various plants to supplement our diets and provide some of the other vitamins and nutrients that we need to survive and be healthy. They also knew which to avoid completely as being unbenefical or dangerous. The last two categories make up the vast majority of plant life on the planet. Eating leaves from a birch tree will do nothing for us. The pits and leaves from Peach and cherry trees? They contain Cyanide. Really. Some of the tastiest fruit contain a tint of poison.

Farming aside, it is probable that some sort of worldwide disaster will require at least a bit of scavenging in order to assure survival. And after we've spent centuries to bend our food-crops to our wills, we've weakened them to the point that they need us in order to survive and propagate. In many cases, I've heard, some of those plants don't even form seeds. Most of our current crops, due to our farming techniques, require constant attention and application of chemicals. When we stop tending them, the crops are going to collapse.

Now, that's assuming that a crop collapse isn't what brought around the apocalypse in the first place. We've grown into a culture of Monoculture. That is, a single variety of plants are widely used. And only that variety. Most are clones of one common plant, as is extremely popular in fruit trees. This is good in the fact that it has expanded our food production vastly as we've honed in on the most successful and productive varieties of plants.

Potatoes are an example of this. The Inca people developed scores of varieties of the potato. They were bred to grow on different parts of the mountain, and to resist different diseases. Then, you have the other half of the spectrum. Ireland in the early 1800s. They lived mostly on potatoes, to the point that it has become a stereotype. Potatoes are easy to grow, and they provide excellent nutritional energy. Then, the potato blight hit. Ireland lost a quarter of its population to either starvation or migration.

But this has all gotten off topic slightly. The point being, that we can't really rely on field crops for sustenance during and after a collapse. Which doesn't get around the fact that, to remain healthy, we need the elements which these plants provide us. And unless you plan to take up farming, you're going to need to find another way to get these supplements into your diet. Unless the entire plant kingdom is burned away, then there's a lot of learning to do before hand. As one miss-step can be perilous.

Now, there's the subdivision of the topic/skill set here. Herb Lore. Great that you can identify the plants. But you also need a grasp on what their qualities are. What part of the common dandelion is edible? All of it. What plants might help relieve a headache? And if the need arises and you find yourself in a bad way amongst some worse villains, what can be used as a poison? Trial and error will teach you what you need to know with time. Assuming that you have time, or don't make the wrong trial. Nothing though beats experience. Not even a encyclopedia with bright and glossy photographs and a couple paragraphs of information.

Is that cannabis you're smoking, hemp or oregano? Or maybe you picked out some poison ivy. Dumb-assed stoner.

Oh. Unless you know for absolute certain, stay away from mushrooms. They're not technically part of the plant kingdom, but some of them are edible(and some people thing delicious). The problem is, many are deadly poisonous. And it's tough to tell which is which at times, especially with the varieties that closely resemble one another.