Being a compendium of trees and herbs from countless spiritual traditions, this exhaustive Herbal of esoteric botany examines in detail the folklore, magical uses and spiritual essences of the vegetal kingdom. While presenting the material through both magical and mythopoetic narrative, the stance of the book is also grounded firmly in supportive disciplines such as botany, chemistry, and anthropology, and also includes up-to-date phylogenetic and pharmacological findings. The text focuses especially upon the Doctrine of Plant Essence, and how those powers are utilized in the active practice of magic and sorcery.

Interspersed with encyclopedic plant entries are short narratives addressing such concepts as the Witches’ Flying Oinment, intoxicating incense, the herbal dimension of Alchemy, and the ‘Green Saints’ such as Al-Khidir, the medieval Wildman, and the forest-dwelling Nymphs who nourished the Greek gods. More than a mere collation of previously existing works on plants, much of the material is drawn directly from the author's private field notes, diaries, and manuals of magical operation from 1991-2016. Among the Twenty-Seven essays included within are 'Devils in the Basilica,' 'The Meaning of Viriditas', and 'The Rhabdomantic Art.' Also present is a special inclusion of a text entitled The Dream-Book of Sylvanus.