Herbalist?

from wikipedia
An herbalist is:

1. A person whose life is dedicated to the economic or medicinal uses of plants.
2. One skilled in the harvesting and collection of medicinal plants (see wildcrafter).
3. Traditional Chinese herbalist: one who is trained or skilled in the dispensing of herbal prescriptions; traditional Chinese herb doctor. Similarly, Traditional Ayurvedic herbalist: one who is trained or skilled in the dispensing of herbal prescriptions in the Ayurvedic tradition.
4. One trained or skilled in the therapeutic use of medicinal plants.