Dryopteris filix-mas fronds range from 30-120 cm long
and 10-30 cm wide. The blades are pinnate-pinnatifid to bi-pinnate
and conspicuously narrowed at the base, the lower pinnae less
than 1/2 the length of the the longest pinnae. The stipe is less
than 1/4 the length of the frond. The stipe bears 2
distinct types of scales, one broad and the other extremely
narrow and hair-like.
D. filix-mas is known from Texas to Arizona and north
to Montana, Washington and British Columbia, and from scattered
localities across the northeastern U.S. and eastern Canada. It
has been identified as a "special concern" species
in Wisconsin where it has been documented from Ashland, Iron and
Brown Counties. The Brown County specimen is correctly identified,
but the location is probably in error, perhaps due mixing of vouchers
and subsequent mislabeling.