Merging the scientific discipline of botany with ancient, medieval, and Renaissance traditions of occult herbalism, this seminal guide was first published in French in 1902 as a textbook for students of Papus's École hermétique and sparked a revival in the study of magical herbalism in early twentieth-century France. Author Paul Sédir, pseudonym of Yvon Le Loup (1871-1926), explains the occult secrets of phytogenesis (the esoteric origin and evolutionary development of the plant kingdom), plant physiology (the occult anatomy of plants), and plant physiognomy (classification of plants according to the doctrine of signatures). Unveiling the mysteries behind planetary and zodiacal attributions, he provides readers with the keys to make their own informed determinations of the astral properties of plants. Moving from theory into practice, Sédir explores various methods of phytotherapy and plant magic, including the Paracelsian "transplantation of diseases," the secret ingredients of witches' ointments, and the composition of magical philters. In the third section of the book, Sédir offers a dictionary of magical plants that covers nearly 300 plant species with descriptions of their astral signatures, occult properties, and medico-magical uses. Compiled from an array of rare sources and esoterica, this classic text includes a wealth of additional materials and supplemental charts and diagrams drawn from Sédir's occult colleagues, all of whom adopted and expanded upon Sédir's pioneering system of plant correspondences.