| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Raphanus sativus | Root | -- | -- | * | |
| Rheum rhabarbarum | Pt | -- | 6.0 | * | |
| Rheum rhabarbarum | Root | -- | -- | * | |
| Sinapis alba | Seed | -- | -- | * | |
| Solanum tuberosum | Tuber | -- | 3.0 | Jim Duke's personal files. | |
| Sophora japonica | Plant | -- | -- | * | |
| Theobroma cacao | Plant | -- | -- | * | |
| Triticum aestivum | Seed | 14.0 | 15.0 | -0.6 | * |
| Urtica dioica | Leaf | -- | -- | * | |
| Urtica dioica | Plant | -- | -- | Jim Duke's personal files. | |
| Vaccinium myrtillus | Leaf | -- | -- | * | |
| Vicia faba | Plant | -- | -- | * | |
| Viola odorata | Plant | -- | -- | * | |
| Viscum album | Plant | -- | -- | * | |
| Vitis vinifera | Root | -- | -- | * |