Mammillaria ID

This plant was bought in a supermarket, so I believe it is not a rare species. However, I've tried to ID it and had no success until now. Can it be an hybrid?
Thanks in advance

I think you made an excellent purchase, but I cannot help with the ID. It does not look a common species to me though. The picture upload is a little difficult to view, I am not sure of the technical reasons.

my fault. the image is too big. you can zoom out to see the picture

I think Mammillaria sheldonii and similar species might be a suggestion to look into.

As moderator, I can edit members posts, and have changed the images so they fit with the forum.

I think it might be worth taking a look at the Mammillaria A to Z section, and under S, look at the plant shown as Mammillaria swinglei. It looks pretty much the same to my eyes, and as I also have this HK plant, it was what I thought of when I saw your photos.

Of course, M. swinglei has been combined with M. sheldonii, but this specific form is to my eyes just a bit different, although it may only be in the width of the mid-stripe.

Thanks David and Chris for replying.
Indeed, sheldonii / swinglei looks similar to mine.
Remember that I found this plant in the supermarket, so I imagine it is a common species. Would it be the case of sheldonii/ swinglei?

Someone suggested M. hutchinsoniana. What do you think about it?

Thanks Chris for adjusting my photos.

Yes, M. hutchisoniana has flowers that look similar, and though spine counts are not always a good differentiator, I went for swinglei/sheldonii because I counted 18-20 radial spines and 3-4 centrals, one hooked, on your plant. That is closer to the description for sheldonii (9 - 24) than what is found commercially as hutchisoniana (25-35).

Ok! I may have to learn to count the spines...

Where do I find the complete description of spines?

thanks again

I still use John Pilbeam's 1999 book "Mammillaria", which was published by The Cactus File, no longer in print, but second hand books are available on various websites, ebay, etc. It dates from the 1940s, but has some interesting old names.
For some of the less common names, the two volume books by Reppenhagen are also good, in German only, and now quite difficult to find, and expensive.
For a more consolidated view of the genus, the New Cactus Lexicon also has the genus in some detail.

thanks again, Chris

mmcavall, regarding the picture upload, I had my teething problems uploading pictures here, I think I have got it now, but I wonder, when you posted, whether you selected a pixel size from the choice available: host an image icon, select item, then choice of pixel size, send image, select middle of the three addresses, then copy paste into the dialogue box. that is the method which worked for me.

i like your Mammillaria, I do not think it is "common", it is a very nice plant.

thanks, David. Hope to have seeds soon!

Hi, David,
if you are still in Brazil, I can send you a bud of this Mammilaria. I have about 5 individuals that are all clones of this plant, and it would be a pleasure to share this with you. Send me a PM

Thank you for offer of the bud. I will be in Brazil this December.