Notocactus ottonis var. elegans Backeb. & Voll in Arch. Jard. Bot. Rio de Janeiro 9: 172. 1950
Notocactus ottonis var. elegans in Arch. Jard. Bot. Rio de Janeiro 9: 172. 1950
is basionym for Notocactus ottonis f. elegans in Repert. Pl. Succ. 14: 11. 1990