What is the importance of "medicinal herbs" in the nonfiction book, Witches, Midwives, and Nurses?

Medicinal herbs were a significant part of the practice of female lay healers throughout history. When contrasted to the religious-based tools and treatments of medieval doctors, medicinal herbs represent an empirical approach to healthcare which was otherwise lacking at the time. As knowledge regarding the use of medical herbs was passed from person to person rather than through formal schooling, the use of these treatments also represents a populist medical practice deemed "unofficial" by the ruling classes despite its efficacy. Ehrenreich and English highlight the efficacy of the female lay healer's empirical approach to medicine in the medieval period by mentioning how some of these traditional herbal remedies still factor in to contemporary treatments centuries later. For example, medieval midwives used ergot to ease labor pains and, today, ergot derivatives "are the principle drugs used today to hasten labor and aid in the recovery from childbirth" (47).