| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Crataegus laevigata | Plant | -- | -- | Leung, A. Y. and Foster, S. 1995. Encyclopedia of Common Natural Ingredients 2nd Ed. John Wiley & Sons, New York. 649 pp. | |
| Crataegus rhipidophylla | Shoot | -- | -- | * | |
| Crataegus rhipidophylla | Fruit | -- | -- | * | |
| Crataegus laevigata | Fruit | -- | -- | * | |
| Crataegus laevigata | Shoot | -- | -- | * | |
| Crataegus rhipidophylla | Inflorescence | -- | -- | * | |
| Crataegus rhipidophylla | Leaf | -- | -- | * | |
| Crataegus monogyna | Plant | -- | -- | Jeffery B. Harborne and H. Baxter, eds. 1983. Phytochemical Dictionary. A Handbook of Bioactive Compounds from Plants. Taylor & Frost, London. 791 pp. | |
| Crataegus laevigata | Leaf | -- | -- | * | |
| Croton lechleri | Plant | -- | -- | * | |
| Ephedra sinica | Stem | -- | -- | Jim Duke's personal files. | |
| Fagopyrum esculentum | Tissue Culture | -- | -- | * | |
| Fagopyrum esculentum | Root | -- | -- | * | |
| Fagopyrum esculentum | Seed | -- | 26.0 | * | |
| Ginkgo biloba | Leaf | -- | -- | Jim Duke's personal files. | |
| Humulus lupulus | Fruit | -- | -- | * | |
| Hypericum perforatum | Plant | -- | -- | Williamson, E. M. and Evans, F. J., Potter's New Cyclopaedia of Botanical Drugs and Preparations, Revised Ed., Saffron Walden, the C. W. Daniel Co., Ltd., Essex UK, 362 pp, 1988, reprint 1989. | |
| Juniperus communis | Fruit | -- | -- | * | |
| Laurus nobilis | Leaf | -- | -- | * | |
| Malus domestica | Fruit | -- | -- | * |