I don't believe this is 'Scarlet Ball.' I think it might be a Parodia (not certain), but I believe it's another species of Parodia.

@zuzu, I don't believe Orsola has been on here since 2016 (well, at least posting). There are three other images that Orsola posted that I don't believe fit this species of Parodia. I was just tagging you in case Orsola doesn't respond at some point. I'm unsure where to place the pictures as I'm unsure if they are that of a Parodia (is there a generic "cactus" entry? ).

Orsola never did much posting, but she proposed that some photos be moved just 6 months ago, so we'll give her a day or two to respond.

Orsola has not responded. Can @skopjecollection and @BlueOddish tell us what they think? Is it a Parodia?

Yes on parodia. And original parodia to boot( red flowered). First- there is a yellowish version of P.hasselbergii with lime yellowish flowers...but, the way I see it, this could also be P. microsperma or P.peniciliata.

Thank you, Stefan. So there's a chance that her photos ("the yellowish version") are in the right place?

Im leaning towards ...not. The photos from @Joy are of the correct plant(parodia h. subsp. graessneri), but these ones might be more parodia penicilata nivosa(since I did have that plant too) rather than graessneri. The thing about graessneri is that it is generally flatter, wider and more solitary than plain haselbergii , with longer yellow-brown spines to boot.

I stand corrected about Joy's plants (also, sorry Joy ).

I'll move Orsola's photos to the generic Parodia entry. Thank you, Hamwild and Stefan.