L. E. Horton Research Natural Area Establishment Record

The L. E. Horton Research Natural Area is distinguished by an assemblage of plant associations that are underlain by ultramafic soil derived either from peridotite or gabbro. The entire RNA is within the Josephine Peridotite Body, a huge mass of peridotite, cumulate gabbro, diabase, and spilite. Forests on peridotite and serpentine show strikingly different patterns from those on adjacent metamorphic and granitic parent materials. The chemical imbalance of the ultramafic soils derived from this parent material is responsible for the open, stunted, scrubby and endemic-rich flora of the area.