| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Mentha spicata | Leaf | -- | -- | Duke, J. A. Writeups or information summaries on approximately 2,000 economic plants, USDA, ARS, Beltsville, MD 20705. | |
| Populus tacamahacca | Plant | -- | -- | * | |
| Rosa centifolia | Essential Oil | -- | -- | * | |
| Mentha spicata | Essential Oil | -- | -- | * |