This makes me think of the things that are already growing in the forests in my area (Missouri) like Nettles which makes an incredibly nourishing bright green herbal tea... Spring things like chickweed and cleaners... Summer things like wild bergamot... Solomons seal is abundant in our woods, but used more topically rather than as a tea. Motherwort I have found growing wild in the woods too. Comfrey is a good one for planting in your grown food forest, it covers alot of ground and is a nitrogen fixer and good useful medicinal!
Gosh theres more but I can't think of them right now! Loving this thread, thanks!