| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Aspalathus linearis | Leaf Essent. Oil | -- | 240000.0 | * | |
| Micromeria juliana | Leaf | -- | 75.0 | 1.0 | Kirimer, N., Ozek, T., and Baser, K.H.C. 1991. Composition of the Essential Oil of Micromeria congesta. J. Ess. Oil Res., 3: 387-393. |
| Vanilla planifolia | Fruit | -- | 19.0 | * | |
| Mentha x piperita | Leaf | 0.01 | 0.1 | -1.0 | Duke, J. A. Writeups or information summaries on approximately 2,000 economic plants, USDA, ARS, Beltsville, MD 20705. |
| Pogostemon cablin | Leaf | -- | -- | * | |
| Ruta graveolens | Plant | -- | -- | * | |
| Cinnamomum aromaticum | Plant | -- | -- | * | |
| Sesamum indicum | Seed | -- | -- | Jim Duke's personal files. | |
| Agathosma betulina | Leaf Essent. Oil | -- | -- | * | |
| Glycyrrhiza glabra | Root | -- | -- | * | |
| Nicotiana tabacum | Leaf | -- | -- | ANON. 1948-1976. The Wealth of India raw materials. Publications and Information Directorate, CSIR, New Delhi. 11 volumes. | |
| Ligustrum japonicum | Flower | -- | -- | * | |
| Cinnamomum aromaticum | Bark | -- | -- | Wealth of India. | |
| Aspalathus linearis | Leaf | -- | -- | * | |
| Zea mays | Seed | -- | -- | * | |
| Camellia sinensis | Leaf | -- | -- | * | |
| Coffea arabica | Seed | -- | -- | CRC Handbook of Medicinal Herbs and/or CRC Handbook of Proximate Analyses | |
| Aspalathus linearis | Plant | -- | -- | * | |
| Guaiacum sp. | Resin, Exudate, Sap | -- | -- | * | |
| Capsicum annuum | Fruit | -- | -- | * |