| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Brassica oleracea var. gemmifera | Stem | -- | 0.012 | -0.4 | * |
| Brassica oleracea var. italica | Stem | -- | 0.015 | -0.4 | * |
| Brassica oleracea var. botrytis l. | Leaf | -- | 0.024 | -0.4 | * |
| Bupleurum chinense | Root | -- | -- | * | |
| Capsicum annuum | Fruit | 0.001 | 0.002 | -0.4 | * |
| Carica papaya | Fruit | 0.1 | 1.0 | -0.1 | * |
| Carthamus tinctorius | Flower | 0.3 | 2.0 | -0.5 | * |
| Carya ovata | Seed | -- | 0.02 | -0.3 | * |
| Carya illinoensis | Seed | -- | 0.02 | -0.3 | * |
| Caulophyllum thalictroides | Root | 0.4 | 3.5 | -0.1 | * |
| Centella asiatica | Leaf | 0.1 | 1.2 | -0.3 | * |
| Chamaemelum nobile | Flower | -- | -- | * | |
| Chondrus crispus | Plant | -- | 18.0 | 0.4 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Chrysanthemum parthenium | Plant | -- | -- | * | |
| Chrysanthemum parthenium | Leaf | 0.3 | 1.7 | -0.3 | * |
| Cichorium endivia | Leaf | 0.008 | 0.024 | -0.4 | * |
| Cimicifuga racemosa | Root | 0.7 | 3.2 | -0.1 | * |
| Citrus paradisi | Fruit | -- | 0.027 | -0.4 | * |
| Citrus sinensis | Fruit | -- | 0.002 | -0.4 | * |
| Citrus reticulata | Fruit | -- | -- | -0.4 | ACTA AGRIC SCAND SUPPL 22: 1980 |