Plant | Low PPM | High PPM | StdDev | *Reference | |
---|---|---|---|---|---|
Abies alba | Resin, Exudate, Sap | -- | -- | * | |
Pinus strobus | Resin, Exudate, Sap | -- | -- | * | |
Pinus palustris | Resin, Exudate, Sap | -- | -- | Leung, A.Y., Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, John Wiley & Sons, New York, 1980. |