| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Pisum sativum | Seed | -- | -- | * | |
| Ricinus communis | Seed | -- | -- | Duke, J. A. Writeups or information summaries on approximately 2,000 economic plants, USDA, ARS, Beltsville, MD 20705. | |
| Rosmarinus officinalis | Plant | -- | -- | * | |
| Ruscus aculeatus | Rhizome | -- | -- | * | |
| Ruscus aculeatus | Root | -- | -- | * | |
| Theobroma cacao | Leaf | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Urtica dioica | Plant | -- | -- | Blaschek, W., Hansel, R., Keller, K., Reichling, J., Rimpler, H., and Schneider, G. eds. 1998. Hager's Handbuch der Pharmazeutischen Praxis, Auflage Band 2 (A-K), 909 pp., (L-Z), 858 pp. Springer-Verlag, Berlin. | |
| Vitis vinifera | Leaf | -- | -- | * | |
| Zea mays | Silk Stigma Style | -- | -- | * |