| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Pistacia vera | Seed | -- | 1450.0 | 1.1 | * |
| Pisum sativum | Seed | 2.0 | 59.0 | -1.1 | * |
| Plantago psyllium | Seed | -- | -- | * | |
| Plantago major | Seed | 3.0 | 8.2 | -1.1 | * |
| Polygonum multiflorum | Root | -- | -- | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. | |
| Prunus dulcis | Seed | -- | 960.0 | 0.4 | * |
| Prunus persica | Fruit | 4.0 | 30.0 | -0.5 | * |
| Prunus domestica | Fruit | 2.0 | 62.0 | -0.4 | ACTA AGRIC SCAND SUPPL 22: 1980 |
| Prunus persica | Bark | -- | -- | * | |
| Pyrus communis | Fruit | 2.0 | 20.0 | -0.5 | * |
| Quercus rubra | Stem | 68.0 | 2442.0 | 1.4 | * |
| Quercus rubra | Seed | -- | 20.0 | -1.1 | * |
| Quercus alba | Bark | 0.4 | 1.6 | -0.6 | * |
| Raphanus sativus | Root | 10.0 | 425.0 | 1.6 | * |
| Rheum rhabarbarum | Pt | 3.0 | 200.0 | * | |
| Rhodymenia palmata | Plant | -- | 368.0 | 1.7 | * |
| Ribes rubrum | Fruit | 10.0 | 312.0 | 0.4 | * |
| Ribes nigrum | Fruit | 10.0 | 220.0 | 0.1 | ACTA AGRIC SCAND SUPPL 22: 1980 |
| Ribes uva-crispa | Fruit | 1.0 | 42.0 | -0.5 | * |
| Rosa canina | Fruit | -- | -- | * |