| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Colocasia esculenta | Leaf | 69.0 | 3625.0 | -0.1 | * |
| Corchorus olitorius | Leaf | 370.0 | 4080.0 | -0.1 | * |
| Coriandrum sativum | Fruit | -- | 920.0 | -0.2 | * |
| Coriandrum sativum | Leaf | 780.0 | 6290.0 | 0.1 | * |
| Corylus avellana | Seed | 10.0 | 22.0 | -0.3 | * |
| Corylus avellana | Leaf | -- | -- | * | |
| Crataegus laevigata | Fruit | 24.0 | 85.0 | -0.3 | * |
| Crataegus rhipidophylla | Fruit | -- | 85.0 | -0.3 | * |
| Crataegus rhipidophylla | Leaf | -- | 1800.0 | -0.3 | * |
| Crataegus laevigata | Leaf | 166.4 | 1800.0 | -0.3 | * |
| Cucumis melo | Fruit | 397.0 | 4370.0 | -0.0 | USDA's Ag Handbook 8 and sequelae) |
| Cucurbita pepo | Flower | 280.0 | 5773.0 | 0.9 | USDA's Ag Handbook 8 and sequelae) |
| Cucurbita spp | Fruit | 148.0 | 2340.0 | -0.1 | * |
| Cucurbita pepo | Fruit | 90.0 | 1071.0 | -0.2 | USDA's Ag Handbook 8 and sequelae) |
| Cuminum cyminum | Seed | -- | 76.0 | -0.3 | * |
| Cuminum cyminum | Tissue Culture | -- | -- | * | |
| Cuminum cyminum | Fruit | -- | 76.0 | -0.3 | * |
| Curcuma longa | Plant | -- | -- | * | |
| Curcuma longa | Rhizome | -- | 293.0 | -0.3 | CRC Handbook of Medicinal Herbs and/or CRC Handbook of Proximate Analyses |
| Cyamopsis tetragonoloba | Shoot | -- | 2800.0 | -0.2 | CRC Handbook of Medicinal Herbs and/or CRC Handbook of Proximate Analyses |