Arnica louiseana var. mendenhallii (Rydberg) Maguire
Arnica louiseana var. mendenhallii (Rydberg) Maguire is a synonym sensu FNA Ed. Comm., 2006c of:
Arnica griscomii subsp. frigida (C.A. Meyer ex Iljin) S.J. Wolf, an accepted subspecies name sensu FNA Ed. Comm., 2006c.