| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Tilia sp. | Flower | -- | -- | * | |
| Malva neglecta | Plant | -- | -- | * | |
| Glycyrrhiza glabra | Root | 4.0 | 34.0 | * | |
| Bacopa monnieri | Plant | -- | -- | Wealth of India. | |
| Crataegus laevigata | Fruit | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Crataegus rhipidophylla | Fruit | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. |