References:
Grieve, M. (Maud). A Modern Herbal; the Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation and Folk-Lore of Herbs, Grasses, Fungi, Shrubs, & Trees with All Their Modern Scientific Uses. New York :Harcourt, Brace & company, 1931.
Image attribution: Pivari - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=13708911