| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Agathosma betulina | Leaf | -- | -- | * | |
| Ageratum conyzoides | Plant | -- | -- | J.S. Glasby Dict.Pls Containing 2ndary Metabolite. 1991. | |
| Brassica nigra | Leaf | -- | -- | * | |
| Trigonella foenum-graecum | Plant | -- | -- | * | |
| Ulex europaeus | Flower | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. |