Al, the magnimamma and compressa "groups" of Mamms are highly variable, particularly when you consider the long list of synonyms now included in both species. (BTW, desert tropicals lists centricirrha as a species in its own right, as well as a synonym of magnimamma!!, and I can't even find a reference to it on mammillarias.net) I happen to agree with s&b as there are a number of forms, that have quite tortuous (twisty) spines. I think you have a lovely plant there, be prepared, it can grow into a huge clump...:)

hmmmm how about mammillaria krameri? i did a search of m Mammillaria magnimamma and saw a pic of krameri i tinhk looks a bit more like this one guess if it blooms that will help . I once had a cacti similar to this one and i havent seen it since it was an odd blue green color had shorter spines and the tubercles were more compact wish i could find even just a picture of it so someone could name it and i could buy one again LoL thanks for the help. Found some pics of the Parodia werneri/Notocactus uebelmanniaus as well can't wait for it to bloom now thanks again

That is a great example of microclimates JoJo! The time spent at the minimum temperature (minutes, hours, days) plays a big role in what temperatures a plant can survive. So does the amount of water in the plant, and in the soil. Dry plants are much more tolerant of cold compared to wet plants. Plants in the ground can survive colder temperatures than plants in pots. I have found most of my plants can tolerate much lower temperatures than typically listed. These lows are brief, just a few hours at most, and it's at least 20 degrees warmer during the day. So plants that are supposed to not go below the mid-thirties F can tolerate minimum temperatures in the high twenties. Agave ferdinand-regis is listed at both +5, and -12 in the list above. The difference between a minimum average temperature, absolute minimum temperature, and Fahrenheit and Celsius scales is often confused. Minimum temperature listings should be regarded with great suspicion, even when coming from a more or less credible source like Desert-Tropicals. It is better to research the plants natural environmental conditions. I would not give much credence to this, or any other so called 'minimum temperature' list. There are too many variables for these to be accurate to any degree. ;) Brad

Those are gorgeous,tell your wife she did a good job.TFS Kathi