This is another of those confusing name situations that are fairly common in the world of hostas. According to The Hostapedia by Mark Zilis (2009), "The registered name of this sport of 'September Sun' is 'Clifford's Polar Moon' but it has been marketed simply as the cultivar, 'Polar Moon'. More correctly, it should be used as a trade name, i.e. H. POLAR MOON."

According to The New Encyclopedia of Hostas by Diana Grenfell and Michael Shadrack (2009), states that H. 'Polar Moon' is a sport of H. 'August Moon'. (But, Zilis says otherwise)