| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Acacia farnesiana | Flower | -- | -- | * | |
| Cinnamomum camphora | Plant | -- | -- | * | |
| Glycyrrhiza glabra | Root | -- | -- | * | |
| Lycopersicon esculentum | Fruit | -- | -- | * | |
| Nicotiana tabacum | Leaf | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Schinus molle | Fruit | -- | -- | * |