Serpentine soil
![Unlike most ecosystems, in serpentine barrens there is less plant growth closer to a stream, due to toxic minerals in the water.](/Images/godic/202502/10/Stream-serpentine-barrens-lancaster-pa3413.jpg")
![Serpentine Barrens in Rock Springs Nature Preserve, Lancaster County, Pennsylvania](/Images/godic/202502/10/Rocksprings-serpentinebarrens-lancaster-pa3413.jpg")
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle. Serpentinite is composed of the mineral serpentine, but the two terms are often both used to mean the rock, not its mineral composition.