I see. Ferocactus latispinus has 2 subspecies so totally 3 latispinus. latispinus, latispinus var. greenwoodii and latispinus var. spiralis. I don't get the differences of 'subspecies' and 'variety' anyway My one could be Ferocactus latispinus var. greenwoodii.

— にがいうり。 (@meloformous) 2018.5.11