Herbal Medicine also known as herbalism is the study and use of medical properties of various Plants. This also includes Fungus and Animal Products/Parts as well as minerals. Plants can synthesize various chemical compounds also called phytochemicals. One example is the salicylic acid also used in aspirin for an example. salicylic acid is used since thousands of years as a pain killer and fever reducer. Actually the phytochemicals are not that different from conventional drugs as they mediate their effects in nearly identical ways. Herbals can be administerd as a liquid from the plants or by whole herb consumption either fresh or dried. Also you can produce Tisanes by extracting the herb into Water. A way to get stronger use of the phytochemicals is by alcoholic extracts of the herb also known as Tinctures their ethanol percantage can go as high as circa 90%. Syrups are extracts of herbs made with syrup or honey. Sixty five parts of sugar are mixed with 35 parts of water and herb. The whole is then boiled and macerated for circa three weeks. Vinegars are very similar to Tinctures, the difference is using acetic acid as the solvent.

How we can use this ingame: We will need to try to make tinctures or tisanes from different plants to observe their effects then we will need to tune the components to create more efficent medicne. In the beggining we most likely are required to consume the herbs withouth any sort of water or ethanol(we wont have ethanol from the beginning unless we find a plant from wich we can extract it.)

References: Various

Ok, various tree barks have that in as well, the Saxons chewed the bark of Oak trees I believe.

I'd outlaw such items, It is a AI option to hunt down illegal goods in your owned land.