Spreading wood fern is a species of fern native to cool temperate and subarctic regions of the Northern Hemisphere to central California in North America. It prefers cool, moist mixed or evergreen forests and rock crevices on alpine slopes, often growing on rotting logs and tree stumps and rocky slopes. It is characteristically riparian in nature, and is especially associated with stream banks. It has a stout, woody, creeping or ascending stock with large, green lacy fronds.