Mammis to identify:

Hi there!!! I put here 3 mammillarias to see if they can help me identify, thanks!  



1) It has 4 yellow central spines, 7 to 10 bicolor radial spines between white, light brown and yellow, wool and few axillary hairs. Columnar with sunken apice.







2) Even small plant, it has 2 to 3 short yellow central spines with light brown tips, 30 to 40 white, crystalline and pubescent radial spines.





3) This mammillaria has 6 radial spines and 1 central spine, all are slightly tortuous, light in color at the base and turning dark red at the tips. Globose shape, has axillary wool.

I think no.1 is possibly m. columbiana, no.2 no suggestion as too small and no.3 maybe m. uncinata.

Mammillaria obscura is a doubtful name and has been placed by some, synonymous with m. petterssonii. I'll be surprised if your plant is indeed a m. petterssonnii type. This would produce red flowers, which would have brown seeds. Whereas, my suggestion would have white flowers, with brown reddish stripes and produce brown seed. We wait and see.