Acorns, become edible after they are fully formed in the fall. The bitter taste that deters many people from using them for food is caused by tannic acid. The unripe acorns that are covering the trees now provide a great source of this healing acid. Pick a few handfuls of green acorns and crack them into pieces. Boil the shells, caps, and nut meat chunks in a pot of water for half an hour. This water should become dark brown and look like tea. Let the liquid cool and use it as a wash for poison ivy, rashes, ingrown nails and hairs, boils, hemorrhoids, and any other inflamed skin condition. You could even use it as a mouthwash--just don't swallow it. Drinking tannic acid can cause nausea and digestive upset. You'll find oaks growing coast to coast throughout the northern hemisphere.
Have you made medicine from wild plants? Tell us what you used in the comments.