| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Mentha spicata | Leaf | 700.0 | 2000.0 | 1.3 | * |
| Mentha aquatica | Leaf | 210.0 | 595.0 | -0.8 | * |
| Mentha pulegium | Plant | 41.0 | 148.0 | Duke, J. A. Writeups or information summaries on approximately 2,000 economic plants, USDA, ARS, Beltsville, MD 20705. | |
| Carum carvi | Seed Essent. Oil | -- | -- | * | |
| Anethum graveolens | Seed Essent. Oil | -- | -- | * | |
| Anethum graveolens | Essential Oil | -- | -- | * | |
| Mentha arvensis var. piperascens | Leaf | -- | 1600.0 | 0.7 | * |
| Mentha x rotundifolia | Leaf | -- | -- | Jim Duke's personal files. | |
| Mentha x piperita | Leaf | -- | -- | Jim Duke's personal files. | |
| Hedeoma pulegioides | Essential Oil | -- | -- | * | |
| Mentha pulegium | Essential Oil | -- | 4100.0 | * | |
| Mentha spicata | Plant | -- | -- | * | |
| Mentha spicata | Essential Oil | -- | -- | * | |
| Valeriana officinalis | Root Essent. Oil | -- | -- | * | |
| Pinus sylvestris | Leaf | -- | -- | * | |
| Melaleuca alternifolia | Essential Oil | -- | -- | * | |
| Mentha japonica | Leaf | -- | 400.0 | -1.1 | * |