| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Ricinus communis | Seed | -- | -- | Duke, J. A. Writeups or information summaries on approximately 2,000 economic plants, USDA, ARS, Beltsville, MD 20705. | |
| Lantana camara | Leaf | -- | -- | * | |
| Cynara cardunculus | Leaf | -- | -- | Jim Duke's personal files. | |
| Aloe vera | Plant | -- | -- | Pakistan Encyclopedia Planta Medica. 1986. | |
| Acacia nilotica | Plant | -- | -- | * |