| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Sorbus aucubaria | Fruit | 360.0 | 1880.0 | -0.4 | * |
| Spartium junceum | Stem | -- | 2600.0 | 0.1 | * |
| Sphenostylis stenocarpa | Seed | 3980.0 | 4393.0 | -0.3 | * |
| Sphenostylis stenocarpa | Root | 800.0 | 2273.0 | -0.2 | * |
| Spinacia oleracea | Plant | 250.0 | 6232.0 | 1.3 | * |
| Spirulina spp. | Plant | -- | 3190.0 | -0.2 | * |
| Spirulina pratensis | Plant | -- | 3190.0 | -0.2 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Spondias purpurea | Fruit | 350.0 | 1680.0 | -0.5 | * |
| Spondias dulcis | Seed | -- | 700.0 | -1.2 | * |
| Spondias pinnata | Fruit | 110.0 | 1135.0 | -0.6 | * |
| Spondias dulcis | Fruit | 670.0 | 5115.0 | 0.6 | * |
| Spondias tuberosa | Fruit | -- | 210.0 | -0.9 | * |
| Spondias mombin | Fruit | 310.0 | 3250.0 | 0.0 | * |
| Stachys officinalis | Plant | 302.0 | 1800.0 | -0.9 | * |
| Stellaria media | Plant | 372.0 | 4480.0 | 0.4 | * |
| Stevia rebaudiana | Leaf | -- | 3180.0 | -0.3 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |
| Stevia rebaudiana | Plant | -- | 980.0 | -1.3 | Kinghorn, A. D. (Ed.) 2002. Medicinal and Aromatic Plants - Industrial Profiles. Stevia. The genus Stevia. Taylor & Francis. New York, NY. 211 pp. |
| Stillingia sylvatica | Plant | -- | 2400.0 | -0.6 | * |
| Symphoricarpos orbiculatus | Stem | 228.0 | 4224.0 | 1.3 | * |
| Symphytum officinale | Root | -- | 2111.0 | -0.2 | Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. |