Treadwell's first ever guidebook has been two years in the making; its author, Christina Oakley Harrington, focused exclusively on actual magical powers attributed to the plants, so this book is full of the old ways plants have been used to achieve love, win competitions, become invisible, see fairies, gain good luck, achieve success, receive protection, and many more.  She consulted over 200 sources for the book, and every spell is footnoted discreetly at the back.
 
London: Treadwells, 2020.  Paperback, 174 pages. New.