Crowea exalatahas 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) l-allyl-2,6-dimethoxy-3,4-rnethylenedioxybenzene (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 ofC. salignacontained croweacin (84–94%) as its principal component with smaller amounts of safrole and terpenes present. A hybridC. exalataxC. salignaalso contained croweacin (82%) as its principal component and possessed an oil very similar toC. saligna.A sample ofC. angustifoliavar.angustifoliaproduced an oil in which the major components were γ-asarone (68%), exalatacin (13%) and croweacin (7%).