| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Catalpa ovata | Wood | -- | -- | Chemical Constituents of Oriental Herbs (3 diff. books) | |
| Catalpa ovata | Tissue Culture | -- | -- | Chemical Constituents of Oriental Herbs (3 diff. books) | |
| Tabebuia impetiginosa | Bark | -- | -- | * | |
| Tabebuia impetiginosa | Heart Wood | -- | 44.0 | * |