| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Adonis vernalis | Plant | -- | -- | * | |
| Andira inermis | Bark | -- | -- | * | |
| Argemone mexicana | Plant | -- | 410.0 | * | |
| Berberis vulgaris | Flower | -- | 6600.0 | Jim Duke's personal files. | |
| Berberis vulgaris | Plant | -- | -- | Jim Duke's personal files. | |
| Berberis vulgaris | Bark | -- | 45000.0 | 1.0 | Jim Duke's personal files. |
| Berberis vulgaris | Leaf | -- | 3000.0 | 1.0 | Jim Duke's personal files. |
| Berberis vulgaris | Stem Bark | 20000.0 | 25000.0 | 1.0 | Jim Duke's personal files. |
| Berberis vulgaris | Root | 4000.0 | 64800.0 | 1.1 | * |
| Berberis vulgaris | Stem | 1600.0 | 28900.0 | Jim Duke's personal files. | |
| Berberis vulgaris | Root Bark | 25000.0 | 80000.0 | * | |
| Caulophyllum thalictroides | Plant | -- | -- | Jim Duke's personal files. | |
| Chelidonium majus | Plant | -- | -- | * | |
| Coptis chinensis | Rhizome | 40000.0 | 90000.0 | 0.9 | * |
| Coptis spp | Rhizome | 40000.0 | 90000.0 | 0.9 | * |
| Coptis japonica | Rhizome | 40000.0 | 70000.0 | -0.3 | * |
| Corydalis spp | Plant | -- | -- | * | |
| Eschscholzia californica | Shoot | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Hydrastis canadensis | Rhizome | -- | 50000.0 | -1.5 | * |
| Hydrastis canadensis | Root | 1385.0 | 60000.0 | 0.9 | * |