| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Chamaemelum nobile | Plant | -- | -- | * | |
| Crataegus laevigata | Bud | -- | -- | * | |
| Crataegus rhipidophylla | Leaf | -- | -- | * | |
| Crataegus laevigata | Leaf | -- | -- | * | |
| Crataegus rhipidophylla | Bud | -- | -- | * | |
| Cuminum cyminum | Seed | -- | -- | * | |
| Ligustrum lucidum | Leaf | -- | -- | * | |
| Matricaria recutita | Flower | -- | -- | Leung, A. Y. and Foster, S. 1995. Encyclopedia of Common Natural Ingredients 2nd Ed. John Wiley & Sons, New York. 649 pp. |