Some of the wild flora growing along Bay Area trails is edible … for instance, I know a wild blackberry and a patch of miner’s lettuce when I see one. Some of it, though, does stuff your body doesn’t like, such as causing major organs to shut down.
Inspired by Sarah at Freezer Bag Cooking’s new page on edible plants, I did some poking around to see what’s growing around the Bay Area. Naturally, Jane at Bay Area Hiker has the topic covered, with pictures of many edible plants. She also recommends two books: “The Flavors of Home: a Guide to Wild Edible Plants of the San Francisco Bay Area” 
Another interesting site: Wild Food Adventures out of Oregon. This tidbit is good to know:
Once you learn to identify “edible” plants (see our Identification and our Edibility pages), you should always check that edible plant’s toxicity. Yes, you heard me right – toxicity. Not all “parts” of a “wild food” are edible. While you may be able to eat the ripe fruit of a plant, the unripe fruit, or the whole rest of a plant may be poisonous! Sometime books focused on wild foods do not mention the parts of an “edible plant” that are poisonous.
That’s from Wild Food Adventures’ poisonous plants page.
That’s enough to make you appreciate the charms of a nice bag Green Giant frozen peas.
Sarah’s page also delves into the ethics of eating wild plants — particularly berries, which are highly prized (by bears, I might add).
There are just so many berries that a human can pick at once with their hands. For one, stooping over picking hurts your back and legs. Add in that berries grow on ridge sides where one cannot go off trail easily to get them, well, there are millions of berries left for the birds, bears and Big Foot to fatten up on. In many places the limit is a quart of berries per person, per day and it takes me all day to pick that. I often pass thousands of rotting berries late in the season, us humans picking by hand are not going to strip the bushes in most cases.
The issue in over picking is in drive up areas where commercial pickers head to. They often use special rakes that strip the plants. Live by the theory of 2-3 berries per plant and you won’t take too many. Obey pick limits, get a permit if required, pick where you have to walk in, not drive up to, don’t step on plants or create ‘casual’ paths to get to them, and NEVER pick in areas where there are Tribal picking treaties.
And if you encounter a bear while picking (which I have) just remember this: they are bigger, badder and they live there – so they get first dibs.”
OK, so there may not be any tribal treaties in our neck of the woods.
The complexities and hazards of eating wild stuff explain why it makes so much sense to pay a farmer to do the picking for you. But part of the pleasure of being out among wild things is knowing what all those plants are, and whether you can chomp into one to stave off starvation. Can’t hurt to know.