Where did you first learn of how plants can be used as medicines?

Answer 1

Trial and error.

Each new plant that came into their awareness was tested, first by tasting, then by ingesting a small amount, monitoring their reactions to be sure the plant was not toxic. As for external use, most likely when a cut happened, the closest thing was used to wipe it and or bind it, if a particularly good response came about the plant was remembered.

Answer 2

Observation augmented by trial and error.

Many plants with similar leaves, stems, flowers etc. have similar properties. By watching the local animals it was possible to ascertain which plants were indigestible. Most plants were originally looked at as food, but some of them had other effects.

The trial and error part starts by checking the scent - you can usually figure out if a plant will taste good from that.

Next you touch it to your tongue - carefully monitor all reactions.

If you get no adverse effects you can take a very small taste. All along you monitor your reactions.

Eventually you know how a plant will effect a person.

From there you can extrapolate on other plants within the same plant family. Proceeding always with the smell, touch, taste and ingest system mentioned above.

Answer 3

I don't remember exactly.

For as long as I can remember I have collected books on the subject of wild edible and medicinal plants - the sort people buy for identifying plants while out hiking. Then I found a college near where I lived that offered an in depth (four years) study of herbal medicine and immediately signed up. It was hard work, but I got through those years of education and opened my own practice as an herbalist.