It was a really cool experience to check out different plants and see which ones were used as food or for other purposes by the native Americans. One thing I'd like to stress though is that this is in California, I can't guarantee that a plant that looks like one of these is the same thing in other climates or parts of the country, so always do the research and find out about the plants native to your area before taking it for granted that something is safe to eat!
This is the California Bay tree. The trunk looked to me like a sort of grayish color, rough, but not cracked deep at all, I'd actually almost call it smooth but that would be confusing after I said it was kind of rough, there's a little picture down there within the pic. Anyway, Native Americans used to burn the leaves in their sweat lodges in order to mask their scent when hunting. People who aren't hunters probably don't think about how unbelievably easy a deer (or many other animals) can smell a human, so this could be very important in the wild if you needed to hunt discretely.
This one is the Sword Fern. It's differentiated by the tubers, stolons, and rhizomes it produces, the last of which are edible. A Rhizome is a root-like stem that creeps along underground. Stolons are stems that creep above or barely right below the surface of the ground, popping new plants out of their nodes. Tubers, which are roundish-to-oblong food-stores for the plant. A potato is an example of a tuber. As far as I've found, only the rhizomes of the Sword Fern are edible.
This guy is the Black Hawthorne. It's characterized by being a very bushy vertically growing shrub (sometimes even a very small tree) with thin thorny branches and leaves that are serrated (not smooth). The serration can vary from large to small serrations. It also grows little white flowers with green-tinged centers.
The cool thing about this one is that it grows berries that are edible. The berries are reddish when growing and eventually become a deep purple or black when ripe.
The Dwarf Oregon-grape (the darker green plant in the picture below) as you can see attracts animals with it's dark blue grape-like fruits. They're not real grapes, though they resemble them, and while they are edible to humans, they're very bitter. The importance of knowing what plants attract animals is that animals can be food. Considering that most animals have a huge advantage over us as far as self defense mechanisms and the ability to detect and evade us with their heightened sense, it can be a big help to be able to locate a food or water source where you know animals will eventually come around. Anyway, these can also be distinguised by the fact that they bloom yellow flowers in the spring.