| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Rheum palmatum | Rhizome | -- | 0.5 | * | |
| Carica papaya | Fruit | -- | -- | Jim Duke's personal files. | |
| Prunus cerasus | Fruit | -- | -- | * | |
| Capsicum annuum | Fruit | -- | -- | * | |
| Glycyrrhiza glabra | Rhizome Essent. Oil | -- | 114000.0 | * | |
| Glycyrrhiza glabra | Root | -- | 7.0 | Kameoka, H. and Nakai, K. 1987. Components of essential oil from the root of Glycyrrhiza-glabra. Nippon Gogeikagaku Kaishi 61(9): 1119-1122. | |
| Scutellaria baicalensis | Root Essent. Oil | -- | -- | * | |
| Citrus limon | Essential Oil | -- | -- | Lawrence, B.M., Essential Oils 1976-1977, Essential Oils 1978, Essential Oils 1979-1980. | |
| Melissa officinalis | Tissue Culture | -- | -- | Gbolade, A.A. and Lockwood, G.B. 1991. The Constituents of Melissa officinalis L. Cultures. J. Ess. Oil Res., 3: 111-114. | |
| Rosmarinus officinalis | Resin, Exudate, Sap | -- | -- | * |