Crowea exalata has been found to exist in five chemical forms. These were forms in which the principal components were: (a) safrole (81-88%), (b) (E)-methyl isoeugenol (18-25%) and (E)-carpacin (47-51%), (c) safrole (27-35%), (E)-methyl isoeugenol (29-46%) and α-pinene (12-25%), (d) safrole (6-29%) and asaricin (57-74%) and (e) 1-allyl-2,6-dimethoxy-3,4-methylenedioxybenzene (30-43%), for which the common name exalatacin is proposed and croweacin (10-20%). All chemotypes yielded essential oils in 0.3-1.0% yield. The oil of C. saligna contained croweacin (84-94%) as its principal component with smaller amounts of safrole and terpenes present. A hybrid C. exalata × C. saligna also contained croweacin (82%) as its principal component and possessed an oil very similar to C. saligna. A sample of C. angustifolia var. angustifolia produced an oil in which the major components were γ-asarone (68%), exalatacin (13%) and croweacin (7%).