Dryopteris crinalis is a species of fern known as the serpent woodfern. It is endemic to Hawaii, where it is known from the main islands.
There are at least two varieties. The var. podosorus was federally listed as an endangered species of the United States in 2010.USFWS. Determination of endangered status for 48 species on Kauai and designation of critical habitat; Final rule. Federal Register April 13, 2010. There are three populations on Kauai, for a total of no more than 47 individual plants. The fern grows on walls of basalt in wet forests. Fronds grow up to long.
References
External links USDA Plants Profile for Dryopteris crinalis