Code used in spells and recipes by Pagans, ancient doctors, alchemists, etc. going back to the Greek Magical Papyri.It means Holly Leaf, which is probably due to the similarity in appearance between an actual bat's wing and the leaf of the plant.
Readers, please enjoy this guest blog post by Sandra Kynes, author of several books, including The Herb Gardener's Essential Guide, Plant Magic, and the new Witches' Encyclopedia of Magical Plants, among many others.
Although a few old books...