| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Senna alexandrina | Leaf | 670.0 | 3300.0 | * | |
| Spartium junceum | Flower | -- | -- | * | |
| Symphytum officinale | Root | -- | -- | * | |
| Taraxacum officinale | Leaf | -- | -- | Hansel, R., Keller, K., Rimpler, H., and Schneider, G. eds. 1992. Hager's Handbuch der Pharmazeutischen Praxis, Drogen (A-D), 1209 pp., 1993 (E-O), 970 pp., 1994 (P-Z), 1196 pp. Springer-Verlag, Berlin. | |
| Tussilago farfara | Leaf | -- | -- | * | |
| Urtica dioica | Root | -- | -- | * | |
| Urtica dioica | Flower | -- | -- | * | |
| Viburnum prunifolium | Bark | -- | -- | * |