Parodia ottonis subsp. horstii
Parodia ottonis subsp. horstii in Cactaceae Consensus Init. 6: 12. 1998 sec. Zappi & Taylor 20201 wfo-0001433525
- ≡Notocactus arechavaletae var. horstii, Kakteen Südamerika 1: 166. 1979 syn. sec. Anceschi & Magli 20182 wfo-0001432862
- ≡Peronocactus ottonis subsp. horstii in Sukkulenty 2(2): 21. 1999 syn. sec. Anceschi & Magli 20182 wfo-0001433638
- ≡Notocactus ottonis subsp. horstii in Sukkulenty 3: 55. 2000 syn. sec. Anceschi & Magli 20182 wfo-0001432959
- –Notocactus spegazzinii var. horstii in Kaktusy (Brno) 46: 102. 2010, nom. inval. syn. sec. Anceschi & Magli 20182 wfo-0001433021