Help ID

[Hamesbest]

I just received the attached cactus from my aunt. It was my grandmother's and she passed away in 1994. I believe the plant is over 50 years old. I hear that it flowers but I don't remember seeing the flowers. It has lived in a drafty north facing window in central Vermont, so it can deal with some cool temps.
The plant is 8" tall (not including the pot/roots) and 5" in diameter. I'd like to get an ID so I can figure out how to keep this alive and possibly repot it into something a bit more fitting to it's stature. Hopefully knowing the type of cactus can help me with what to expect.

Thank you for your help in advance.

[Hamesbest]

One addition, the flowers are a ring at the top of the plant of red or pink flowers.

[anttisepp]

Mammillaria hahniana

[DaveW]

Yes Mammillaria hahniana. The original tall hairy clone we used to get in the UK in the 1960's, but seems less common now unless coming from an old collection. It has to be really tall to pup unlike some of the more recent long haired pupping forms. A species with variable hair length in habitat but of course the more attractive forms get singled out for propagation in cultivation. Clumping form shown lower down this link:-

https://mammillaria.forumotion.net/t115 ... a-hahniana

The forms like M. bravoae, M. mendeliana and M. woodsii are often lumped into M. hahniana as varieties or subspecies these days as merely being longer spined but less hairy forms.

[Hamesbest]

Thank you much for the identification! Hopefullly with this information I can keep it alive.

[greenknight]

Many Mammillarias are shallow-rooted - this is obviously one of those, since it was able to grow so large in such a cramped pot. The pictures of them in habitat DaveW linked to show them growing in rock crevices with very little soil. Do give it a bigger pot, but not too much bigger - less chance of rot if you keep it tightly potted. I killed a number of Mamms before I learned this lesson.