Bay leaf is a popular household spice used in flavoring foodstuff. The true bay leaf is derived from the bay laurel or sweet bay tree, Laurus nobilis, native to the Mediterranean region. However, leaves of several other species including Cinnamomum tamala (Indian bay leaf), Litsea glaucescens (Mexican bay leaf), Pimenta racemosa (West Indian bay leaf), Syzygium polyanthum (Indonesian bay leaf) and Umbellularia californica (Californian bay leaf) are also often sold as 'bay leaves' and are commonly substituted, adulterated or mistaken for the true bay leaves (Laurus nobilis) due to their similarity in appearance, aroma and flavor . Thus, the name 'bay leaf' in herbal commerce may mean any of these botanicals . The present work provides a detailed morpho-anatomical study of different types of bay leaves for correct identification of the true bay leaf and its substitutes. Acknowledgements: This research is supported by Science Based Authentication of Dietary Supplements and Botanical Dietary Supplement Research funded by the Food and Drug Administration grant # 1U01FD004246 – 05. References:  Tabanca N, Avonto C, et al. (2013)J Agric Food Chem 61: 12283 – 12291.  Leung AY, Foster S (2003) Encyclopedia of Common and Natural Ingredients used in Food, Drugs and Cosmetics. Wiley & Sons, Hoboken.