Long term food or healing plants for all times to come.

Good evening friends! I'm looking for more long term crops or plants other than kale, apples and stuff found in food forests. Which plants out there feed and heal us for times good or bad?
Things in the world are rapidly changing and becoming more challenging as time goes on. I'm looking for ones that don't harm the native landscapes around us. Please reach me if you all need me. Good night.

Comfrey is probably the most useful one I've come across - deep tap roots, chop and drop for fertility, and the leaves are genuinely medicinal. Osteopermum and sea kale are worth a look too if you're in a temperate climate. For trees, mulberries are hard to beat for low-maintenance fruit over decades.

What's happening! I like comfrey and would consider it. I already got mulberries in my backyard and community farm and had berries from the tree and taste good.
Could perennial onions such as walking and others work?

I give a second, emphatic vote for sea kale! (Crambe maritima) If you can get your hands on them, they taste pleasantly of the sea. More like sea cabbagey tasting than kaley. They are one of my favorite perennial vegetables I’ve found, and really easy to propagate too—just take a root and stick it in some more soil. They also seem non invasive. The roots are said to be edible too, if you have enough to warrant eating.

If "feed in bad times" means "keep alive in the absence of supply chains", you need calorie-dense crops. Look into the culinary traditions of indigenous people in your area and in climates like yours for ideas.

Sunchokes are a permaculture cliche, but they tick the box for "stays long term" and "stores a lot of calories". They can make it tricky to grow other things where you plant them, but few to no climates have problems with sunchokes randomly wandering off into the woods and outcompeting native species there.

Cattails are less widely utilized, but the rhizomes are a good starch. If you can encourage a wet spot somewhere in your garden to stay wet year-round, you may be able to introduce them.

If your climate likes potatoes, it might also like the other south american tubers like yacon and oca.

"healing" means many things to many people. If you're on long-term prescriptions, consider researching any plants from which the compounds in them are derived, and get familiar with the variability in botanically sourced medicines versus industrially sourced ones. plenty of traditional garden herbs have medicinal traditions associated, and the failure mode of small doses is more "doesn't do anything" than "kills you" for the ones we consider edible.

for disinfection, look back to where people got their booze in your region before modern supply chains. alcohol is a powerful cleaning product, and if you're cleaning with it rather than drinking it, you don't have to worry about the "and if you mess this up you go blind" parts of the distillation process.

and if you're looking into holistic plant-enhanced quality of life for prospective bad times, try a bunch of plants whose leaves people claim make good toilet paper, and cultivate an excess of your favorite. Grow lots of them around your outhouse, just in case.

You probably have some around already, as people plant them ornamentally, but Pachysandra terminalis has been researched for its activity against liver cancer, and I treat them as a liver and blood tonic, and have found them very beneficial. I suspect that because the research is in its infancy, many other uses will be found for them (though allopathic medicine has a different approach to things than the way I typically think of things and have found most useful). I find them to be safe, but they have no traditional uses known so it would be good to have some caution if trying for the first time.

They have edible berries too, if you can get two plants, a male and a female, to cross-pollinate. I have never tried, but heard that they’re good.

Blake Lenoir wrote:Could perennial onions such as walking and others work?

The walking onions are fantastic. In our climate, they are great 11 months of the year and would still be edible the one cold month we have if need be. They are very versatile and basically fool proof.  

I would rank them #2 after #1 Comfrey. Kale would be #3.