Dryopteris expansa

Dryopteris expansa, the alpine buckler fern, northern buckler-fern or spreading wood fern, is a species of perennial fern native to cool temperate and subarctic regions of the Northern Hemisphere, south at high altitudes in mountains to Spain and Greece in southern Europe, to Japan in eastern Asia, and 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.