| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Chrysanthemum parthenium | Plant | -- | -- | * | |
| Cymbopogon nardus | Plant | 198.0 | 792.0 | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Picea mariana | Twig | -- | 46.0 | * | |
| Tanacetum parthenium | Plant | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Thymus vulgaris | Plant | -- | -- | ANON. 1948-1976. The Wealth of India raw materials. Publications and Information Directorate, CSIR, New Delhi. 11 volumes. | |
| Tsuga canadensis | Branches | -- | -- | * |