| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Acacia farnesiana | Plant | -- | -- | Rizk, A.F.M. and Al-Nowaihi, A.S., The Phytochemistry of the Horticultural Plants of Qatar, Scientific and Applied Research Centre, University of Qatar. | |
| Anastatica hierochuntica | Plant | -- | -- | * | |
| Brassica oleracea var. capitata l. | Leaf | -- | -- | Jim Duke's personal files. | |
| Maclura pomifera | Fruit | -- | -- | Smith, J. L. and Perino, J. V. 1981. Osage Orange (Maclura pomifera): History and Economic Uses. Economic Botany 35(1): 24-41 | |
| Melaleuca leucadendra | Plant | -- | -- | * | |
| Thespesia populnea | Flower | -- | -- | ANON. 1948-1976. The Wealth of India raw materials. Publications and Information Directorate, CSIR, New Delhi. 11 volumes. | |
| Urginea maritima | Bulb | -- | -- | * | |
| Vicia faba | Fruit | 0.03 | 1.3 | * |