| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Citrus sinensis | Fruit | -- | 2.0 | -1.0 | * |
| Citrus reticulata | Fruit | -- | 58.0 | 1.0 | * |
| Opuntia ficus-indica | Shoot | -- | -- | * | |
| Lophophora williamsii | Plant | -- | -- | * | |
| Hordeum vulgare | Sprout Seedling | -- | 48.0 | * | |
| Hordeum vulgare | Root | -- | -- | * | |
| Citrus reticulata | Pericarp | -- | -- | * | |
| Prosopis glandulosa | Leaf | -- | -- | * | |
| Hordeum vulgare | Fruit | -- | -- | * | |
| Citrus paradisi | Fruit | -- | -- | * | |
| Citrus limon | Leaf | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Citrus sinensis | Pericarp | -- | -- | Jim Duke's personal files. |