| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Agathosma betulina | Leaf | 5250.0 | 8750.0 | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Barosma betulina | Leaf | 5250.0 | 8750.0 | * | |
| Mentha spicata | Essential Oil | -- | -- | * | |
| Agathosma betulina | Leaf Essent. Oil | -- | -- | * |