Christopher Hedley (1946-2017) was a Fellow of the National Institute of Medical Herbalists, and taught herbal medicine at all levels, from beginners to MSc in Herb Schools across the UK and the USA, specialising in material medica and pharmacy.

Guy Waddell PhD fHEA MNIMH is a herbalist and educator who lives and works in London. He is Director of Studies at Heartwood Education, which provides foundation and professional level courses in herbal medicine. Previously, he was a lecturer in herbal medicine in the Department of Life Sciences at the University of Westminster. He has authored The Enchantment of Western Herbal Medicine: herbalists, plants and nonhuman agency (Aeon Books, 2020). He has a particular interest in how humans and plants know each other and what may come of this.