I was first drawn to Hermetic Herbalism: The Art of Extracting Spagyric Essences by Jean Mavéric (in a new translation by R. Bailey) because of my fascination with the very subject described by the title: the influence of hermetic thought on the history of the use of plants for maintaining health.
I have been delightfully surprised by all the inspiration offered by Gail Bussi in Enchanted Herbal: Connect to Nature & Celebrate the Seasons. This book is handy, practical, and filled with wisdom for all the seasons.
Entering Hekate’s Garden: The Magick, Medicine & Mystery of Plant Spirit Witchcraft by Cyndi Brannen is a book about plant spirit witchcraft, a craft which incorporates magick, medicine, and the mystery of botanicals through the use of both their physical properties and their spiritual essence.