Besides the redwood forests and the desert, most of wild California is like an all natural food forest.
Southern California is more so a food forest than northern cal, but Nor Cal is full of edibles too.
The Natives of southern Cal must have had such a different psyche than anyone alive today. To look around you and see that everything was edible for 100s of miles or at the very least was a resource must really elevate ones consciousness out of the pits of Hell, desperation, and neediness up into a higher plane of thinking, feeling, and living.
On any given day though, many things are not in season.
California is the world's largest nut producer, but the wildlands of California produce more acorns than Cal agriculture produces nuts. Walnuts also grow wild, pine nuts, pinion nuts are abundant in their season. Buckwheat bushes produce upto 300lbs of buckwheat per acre. Acorns can be as much as 2000lbs per acre and even more in a good year. This fall in Julian in the Mts of San Diego, the acorns were literally the size of small apples and the ground was covered in them. One tree easily produced 100 lbs of acorn nuts.
Pine trees produce about 250-300 lbs of nut per acre. Shelled obviously.
Nettle is edible. Thistle is edible. Wild lettuce and dock are very abundant. I could easily harvest pounds and pounds of edible salad greens from my yard and so can anyone else in California.
Wild chia is so abundant in so cal that the super food was a staple food for the natives. Sage and all of the countless salvia varieties such as chia, all produce edible seeds.
The variety of wild vetch that grows all over California and this time of the year covers EVERYTHING produces a bean that can be harvested dry to store or eaten green. It is 25% protien. The entire plant is edible.
Of course there is also dandelion and sorrel things like that everywhere also.
Grass hoppers are easy to catch. If you are ever in the need to forage for survival grass hoppers are everywhere and should be your first go-to food source because they have everything you need and they are everywhere. Once you start eating grasshoppers and wild lettuce start collecting your carbs from under an oak. Almost anytime of year you can gather enough acorns to survive. They need to be leached though.
There are also many wild fruits across the state. Nor Cal is super abundant with wild fruit, more so than Hawaii or anywhere I've been at least in the region where I live.
Here there are raspberries, goose berries, elderberries, apples, pears, plums and cherries, Oregon grape, (conventional) wild grapes, huckle berries and of course the ever famous blackberries which there are two varieties of. This is and the salmon is why California is famous for bears.
Southern Cal has alot of gooseberries and Holly leaf plums, elderberries and blackberries.
Yucca stalk and flowers can be eaten. The seeds and roots are antiinflamitories.
Prickly pear cactus and fruits are edible. The fruit is amazing and makes a good probiotic soda pop.
The young yucca stalk can be boiled in water, strained, and evaporated down to sugar.