| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Cucumis sativus | Fruit | 10.0 | 1000.0 | 2.6 | * |
| Cucurbita pepo | Seed | -- | -- | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. | |
| Curcuma longa | Plant | 6.0 | 20.0 | -0.4 | * |
| Cymbopogon citratus | Plant | -- | 132.0 | 0.2 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Cypripedium pubescens | Root | -- | 222.0 | 0.7 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Daucus carota | Root | 1.0 | 91.0 | 0.1 | * |
| Dioscorea sp. | Root | -- | -- | * | |
| Dioscorea villosa | Root | -- | -- | * | |
| Echinacea spp | Root | -- | 8.0 | -0.3 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Echinacea purpurea | Root | 8.0 | 30.1 | -0.2 | * |
| Eleutherococcus senticosus | Root | -- | -- | * | |
| Elytrigia repens | Plant | -- | 253.0 | 1.0 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Ephedra sinica | Plant | 0.7 | 3.1 | -0.5 | * |
| Equisetum arvense | Plant | 8.3 | 38.6 | -0.3 | * |
| Eriodictyon californicum | Leaf | 1.5 | 7.0 | -0.4 | * |
| Eupatorium perfoliatum | Plant | 0.2 | 2.0 | -0.5 | * |
| Euphrasia officinalis | Plant | 5.0 | 30.3 | -0.4 | * |
| Foeniculum vulgare | Fruit | -- | 4.2 | -0.6 | * |
| Foeniculum vulgare | Seed | 0.1 | 0.4 | -1.2 | * |
| Fragaria spp | Fruit | 10.0 | 270.0 | 0.3 | ACTA AGRIC SCAND SUPPL 22: 1980 |