"Serpent rock" due to its greenish color

Over 700 wild plants in California have an affinity for serpentine soil. There is also a disproportionate degree of rarity in serpentine species; of these, about half are rare . From the Calflora home page , check "Affinity to serpentine soil" to see the entire list of species. Scientific names link to species distribution in California, rare plant status, and characteristics.

What is serpentine?

Serpentine soils originate from metamorphic rocks. M agnesium concentrations are high relative to low calcium concentrations in serpentine soils compared to most other soils. This creates a unique environm ent in which limited plant species are able to tolerate the high heavy metals and low nutrient concentrations. Serpentine is sometimes called ultramafic: ma(gnesium) + Latin f(errum) iron + -ic. These plants are unusual because they utilize calcium when the alkaline earth elements are dominated by magnesium, and they tolerate concentrations of cobalt and nickel that are toxic to most plants. Mean ultramafic affinity numbers for plant taxa are listed for each serpentine species in Calflora per Safford and Miller 2020.

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