"Most plants will kill most animals."
Humans are the only species that think they can outsmart nature, stuffing indigestable plant material into our bodies then being shocked when we we get gut problems, skin problems, autoimmune disease, etc.
Plants are highly-evolved bio-weapons of nature, specifically designed to chemically-poison potential predators so they can continue to survive the evolutionary arms race of immobile plants vs. mobile animals.
You do not want to eat these things. If you do, don't be surprised when your body gives you negative feedback, usuallly in the form of chronic pain, inflammation, or mental problems.