[2] The Aleutian shield fern is the only native plant of Alaska on the federal endangered species list.

[4] Polystichum aleuticum was first described in 1938, but it could not be located again until 1975 when a group was identified on Mount Reed on Adak Island.

[5][6] It is unlike any other known shield fern found in North America, and originally it was questioned whether it even belonged to the genus Polystichum.

However, it was found to be similar to a dwarf Polystichum species native to southwestern mountains of China and the Himalayas.

Its leaves, visible during the growing season, are light or dark olive green, and tapering.