Rusty Woodsia

Rusty woodsia, also called oblong woodsia or rusty cliff fern, is a small fern of the cliff fern family Woodsiaceae with a circumpolar range across North America and northern Eurasia, most abundant in Scandinavia, the Ural and Altai mountains, and the eastern United States, with further populations in Japan, Alaska, Canada and Greenland. Its fronds are roughly six inches long by one inch wide, with stiff, pointed tips cut into about twelve nearly opposite, stemless leaflets. The underside of the fronds is covered in white woolly fibers that turn rusty brown with age, the trait behind its common name, and it favors sunny, exposed cliffs and rocky slopes on thin, dry, acidic soil.