| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Cinnamomum camphora | Plant | -- | -- | * | |
| Cinnamomum aromaticum | Plant | -- | -- | * | |
| Glycyrrhiza glabra | Root | -- | -- | * | |
| Guaiacum sp. | Resin, Exudate, Sap | -- | -- | * | |
| Pimpinella anisum | Plant | -- | -- | Newall, C. A., Anderson, L. A. and Phillipson, J. D. 1996. Herbal Medicine - A Guide for Health-care Professionals. The Pharmaceutical Press, London. 296pp. | |
| Prunus dulcis | Flower | -- | -- | * | |
| Syringa vulgaris | Flower | -- | -- | Lawrence, B.M., Essential Oils 1976-1977, Essential Oils 1978, Essential Oils 1979-1980. | |
| Vanilla planifolia | Fruit | -- | -- | * |