| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Citrus reticulata | Fruit | 120.0 | 1773.0 | -0.7 | * |
| Citrus paradisi | Fruit | 150.0 | 3100.0 | -0.2 | * |
| Cnidoscolus chayamansa | Leaf | 2045.0 | 10230.0 | -0.1 | * |
| Coccinia grandis | Flower | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Cocos nucifera | Leaf | -- | -- | Jim Duke's personal files. | |
| Cocos nucifera | Endosperm | -- | -- | Jim Duke's personal files. | |
| Cocos nucifera | Seed | 1720.0 | 3245.0 | -1.4 | USDA's Ag Handbook 8 and sequelae) |
| Colocasia esculenta | Root | 920.0 | 3135.0 | -0.1 | * |
| Corchorus olitorius | Leaf | 1820.0 | 14815.0 | 0.9 | * |
| Coriandrum sativum | Fruit | -- | -- | * | |
| Crocus sativus | Bulb | -- | -- | * | |
| Cryptotaenia japonica | Shoot | -- | -- | * | |
| Cryptotaenia japonica | Root | -- | -- | * | |
| Cucumis sativus | Fruit | 160.0 | 4051.0 | 0.1 | * |
| Cucurbita pepo | Fruit | 440.0 | 6100.0 | 0.9 | * |
| Cucurbita spp | Fruit | 480.0 | 7595.0 | 1.4 | * |
| Cucurbita pepo | Seed | 11480.0 | 19825.0 | 1.8 | * |
| Cucurbita foetidissima | Seed | 12585.0 | 20180.0 | 1.8 | * |
| Daucus carota | Plant | -- | -- | * | |
| Daucus carota | Root | 350.0 | 2865.0 | -0.3 | * |