Permaculture meets native gardening, the best of both worlds
Wouldn't it be nice if we could get all of our calories and nutrients from native plants? We'd be skipping the global supply chains, we wouldn't need fertilizer or massive aquaducts. We'd be taking care of our wildlife at the same time we were feeding ourselves.
Such a dream might be theoretically possible, but our food choices would be limited to the mostly unfamiliar. There are some exception out there though. And lets not forget, before Europeans settled here, there were millions living off the land.
Living off the Land
One thing I've seen since I started participating in the native plant community is that Native Americans are present and actively claiming their heritage.
Native tribes are organized and continue to work hard to make sure their heritage is not forgotten amongst eachother or by the society that has attempted for hundreds of years to erase them.
One effort some tribal groups have taken on is advocating for native plants. And it makes perfect sense. Native Americans took a completely different approach to agriculture than the European tradition of conquer and destroy. They worked the land, but they didn't clear it to make fields of monocrops, or large structures. They lived within it and cultivated in ways more similar to permaculture than agriculture.
And California had more than enough to live off of. Unfortunately, Most of the foods the Native Americans in Calfornia ate did not become part of the modern diet. For example, I find it very strange that we haven't adopted the acorn into our diet. Established oak trees generate thousands of them, each loaded with protein and nutrients that so many animals live off of. Unfortunately, we cut most of them down and made coffee tables and cabinets a long time back.
Native Foods That We Do Eat
There are some native plants that we do consume, or some variation of them. Most people won't try to subsist entirely on native plants, but there are many that could be added to anyone's diet.
For example, California has a native grape, Vitis californicus. It's a true grape and you can eat its berries, but we don't. We do, however, graft with it. Many plantings in wine country are European grapes grafted on Vitis californicus rootstock. Using the wild grape as a rootstock makes for a strong plant that is well adapted to the climate, that still produces that desired pinot noir or zinfandel grape.
Pacific Blackberries, Rubus ursinus, are a significant native fruit. Raspberries are also native to parts of California.
California also has native strawberries. Fregaria vescas, known as "Alpine Strawberries" or "Woodland Strawberries". These produce tiny, very delicious strawberries. There is also the Beach Strawberry, Fragaria chiloensis. Alpine Strawberries were once found in markets, but we displaced when the common hybrid strawberry caught on. They pack gread flavor, most likely they were just too small to be profitable once the larger ones came around. Our common, store bought strawberry is a hybrid that is part Fragaria chiloensis. So still kind of there. These are two of my favorite groundcovers.
Walnut trees are also very edible. Calfornia has two species, the "Southern California Black Walnut" and the "Northern California Black Walnut". They are just as edible as the European Black Walnut, but are said to have a stronger flavor. You probably won't find them in your local grocery store, but you can find them for sale online.
Elderberries have been catching on lately as a health food, believed to fight disease such as flu and cold. Just don't eat the berries raw, they are poisonous unless cooked.
Sage plants are sometimes eaten for their seeds, such as the chia or the black sage. Black sage can be used in place of culinary sage and has a stronger flavor (so you may want to reduce the quantity you use).
Miner's lettuce is a riparian plant that I have seen and eaten in the wild. It's just a mild, green leafy lettuce-like plant that could easily be used anywhere lettuce in place of lettuce on a salad or sandwich.
Golden current makes a sweet, edible fruit.
Huckberry is a close relative to the blueberry, grows better in our climate and produces similar fruit. It isn't found native in many parts of Southern California though.
Coast Prickly Pear Opuntia littoralis cacti produce edible fruits and are commonly found throughout even the non-desert parts of Southern California. This is one you may actually find in some produce sections of stores, especially if you go to a mexican grocery store.