| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Camellia sinensis | Leaf | 960.0 | 32500.0 | 1.4 | * |
| Uncaria tomentosa | Bark | -- | 25.0 | 1.0 | * |
| Malus domestica | Leaf | 150.0 | 900.0 | -0.7 | * |
| Mitragyna speciosa | Leaf | -- | 150.0 | -0.7 | * |
| Cinnamomum verum | Bark | -- | 11.0 | -1.0 | * |
| Rubus idaeus | Leaf | -- | -- | * | |
| Rubus idaeus | Plant | -- | -- | * | |
| Aesculus hippocastanum | Fruit Epidermis | -- | -- | Jim Duke's personal files. | |
| Cinchona pubescens | Bark | -- | -- | * | |
| Aesculus hippocastanum | Leaf | -- | -- | Jim Duke's personal files. | |
| Aesculus hippocastanum | Seed Coat | 816.3 | 4000.0 | Jim Duke's personal files. | |
| Cinnamomum aromaticum | Bark | -- | -- | 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. | |
| Crataegus laevigata | Fruit | -- | -- | * | |
| Crataegus laevigata | Flower | -- | -- | * | |
| Crataegus laevigata | Leaf | -- | -- | * | |
| Crataegus laevigata | Shoot | -- | -- | * | |
| Crataegus laevigata | Bud | -- | -- | * | |
| Humulus lupulus | Fruit | -- | -- | * | |
| Rheum officinale | Rhizome | -- | 3437.5 | * | |
| Crataegus rhipidophylla | Fruit | -- | -- | * |