Formally described in 1891 , it is very similar to Asplenium adiantum - nigrum , which is occasionally found in the adjacent portions of the United States .
Formally described in 1891 , it has sometimes been placed in synonymy with that species .
Formally described in 1891 , it is very similar to Asplenium adiantum - nigrum , which is occasionally found in the adjacent portions of the United States , and has sometimes been placed in synonymy with that species .