| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Achillea millefolium | Leaf | 1.0 | 50.0 | -0.4 | * |
| Acinos suaveolens | Shoot | -- | 50.0 | -0.5 | Tumen, G. 1991. The Volatile Constituents of Acinos suaveolens (Sibt. et Smith). G. Don fil. Growing in Turkey. J. Ess. Oil Res. 3:191-2. |
| Aloysia citrodora | Plant | 150.0 | 1820.0 | 0.4 | Lawrence, B.M., Essential Oils 1976-1977, Essential Oils 1978, Essential Oils 1979-1980. |
| Camellia sinensis | Leaf | -- | -- | Leung, A. Y. and Foster, S. 1995. Encyclopedia of Common Natural Ingredients 2nd Ed. John Wiley & Sons, New York. 649 pp. | |
| Carum carvi | Seed | -- | -- | * | |
| Cinnamomum verum | Stem Bark | -- | -- | * | |
| Cinnamomum aromaticum | Plant | -- | -- | * | |
| Cinnamomum verum | Leaf Essent. Oil | -- | -- | * | |
| Cinnamomum verum | Bark | -- | -- | Lawrence, B.M., Essential Oils 1976-1977, Essential Oils 1978, Essential Oils 1979-1980. | |
| Cinnamomum camphora | Leaf | -- | -- | * | |
| Cistus ladaniferus | Leaf | 27.0 | 1090.0 | -0.2 | * |
| Citrullus lanatus | Fruit Juice | -- | -- | * | |
| Citrullus lanatus | Fruit | -- | -- | * | |
| Citrus sinensis | Fruit | 6.0 | 7.0 | -1.0 | * |
| Citrus limon | Pericarp Essent. Oil | -- | 17600.0 | Jim Duke's personal files. | |
| Citrus limon | Leaf Essent. Oil | 3000.0 | 233000.0 | 1.0 | Jim Duke's personal files. |
| Citrus aurantium | Plant | -- | -- | * | |
| Citrus reticulata | Fruit | 5.0 | 6.0 | -1.0 | * |
| Citrus aurantium | Leaf | -- | 1.0 | -0.4 | * |
| Citrus paradisi | Leaf | -- | 31.0 | -0.4 | * |