Athyrium distentifolium var. americanum (Butters) B. Boivin

Athyrium distentifolium var. americanum (Butters) B. Boivin is a synonym sensu Baldwin et al., 2012 of:

Pseudathyrium alpestre subsp. americanum (Butters) ined., an accepted subspecies name sensu Hassler, 2014-2024+.