| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Uncaria catechu | Branches | -- | -- | * | |
| Uncaria catechu | Leaf | -- | -- | * | |
| Crataegus rhipidophylla | Fruit | -- | -- | Chemical Constituents of Oriental Herbs (3 diff. books) | |
| Crataegus laevigata | Fruit | -- | -- | Chemical Constituents of Oriental Herbs (3 diff. books) |