Two thousands years ago a man who was roman by the name of Dioscorides wrote a book around the year A.D. 77 called De Materia Medica. This book linked plants and medicine to astrology. This was about two thousand years ago before medicine became man made and had to regulated by the FDA. Homeopathy and Astrology are very important medical uses of the plant and astrology gives the association of the matching of the energy patterns.
In the old days many Pagans knew of the old magickal uses of herbs and plants. Knowledge of this was passed from one generation to the next. Through generations upto today knowledge of magickal herbs has become lost. But just recently Witches have become the keepers of the earth. Through the centuries these were fewer and fewer people who wanted to learn. Today there are many who wish to eat healthy and do the medicinal herbs that are found in health food stores. There is one rule that the Pagans use and that is just don't stop using prescription drugs ( like an antibiotic) that the doctor gives you. Most times when you are really sick don't always work but they do work. Pagans who do herbal magick use the herb for its enrgies that it has.
There have been very many uses for herbs. You can use them for protection, beauty, success, and peace. Modern Witches use herbs for magick, natural medicine, health, and healing. The magickal intent of the herb always matches its medical intent.