I think this is the correct species and subspecies for this Pteridium.
The bracken fern (Pteridium aquilinum) is commonly found in moist areas and wetlands. It's distinguishable by its stem splitting into three main fronds at the top and their triangular shape, widest at the base and getting smaller to the pointed ends.
Pteridium aquilinum (bracken, brake or common bracken), also known as "eagle fern," is a species of fern occurring in temperate and subtropical regions in both hemispheres. The extreme lightness of its spores has led to its global distribution.