| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Juglans nigra | Seed | -- | -- | * | |
| Echinacea spp | Plant | -- | -- | * | |
| Annona muricata | Plant | -- | -- | * | |
| Convallaria majalis | Plant | -- | -- | * | |
| Carica papaya | Leaf | -- | -- | Jim Duke's personal files. | |
| Crataegus rhipidophylla | Inflorescence | -- | -- | * | |
| Crataegus rhipidophylla | Flower | -- | -- | * | |
| Crataegus rhipidophylla | Leaf | -- | -- | * | |
| Crataegus rhipidophylla | Shoot | -- | -- | * | |
| Spartium junceum | Plant | -- | -- | * | |
| Crataegus rhipidophylla | Bud | -- | -- | * | |
| Lycopus virginicus | 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. | |
| Stachys officinalis | Shoot | -- | -- | * | |
| Santolina chamaecyparissus | Plant | -- | -- | * | |
| Clematis vitalba | Plant | -- | -- | * | |
| Rubus idaeus | Plant | -- | -- | * | |
| Humulus lupulus | Plant | -- | -- | * | |
| Sambucus nigra | Plant | -- | -- | * | |
| Vaccinium vitis-idaea | Leaf | -- | -- | * | |
| Corylus americana | Seed | -- | -- | Senter, S. D., Horvat, R. J., Forbus, W. R. 1983. Comparative GLC-MS Analysis of Phenolic Acids of Selected Tree Nuts. J. Food Science, 48(3): 798-799. |