Dryopteris intermedia, the intermediate wood fern or evergreen wood fern, is a perennial, evergreen wood fern native to eastern North America. It is a diploid species, and is the parent of several spe

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, sou