M. crispiseta Craig, Mamm. Handbook 308, fig. 280. 1945
Stem simple (or dividing dichotomously?), flattened-globular. withmilky
sap; axils, with long white bristles. Central spines, 4-5 , 7-18mm. long,
acicular, variable in colour from cream to black; radial spines 8, 4-7mm. long,
slender acicular. Fls. undescribed. Fruit clavate 15mm. with dried perianth
persistent; seeds brown.
Mexico: Locality unknown. Described from a living plant obtained
from Schmoll, no. 718.
From the incomplete description and illustration this is clearly one
of the M. karwinskiana group , though the number of spines is unusually high.
I have not encountered it in cultivation, and do not know if it has persisted.
From "The Journal of the Mammillaria Society" Vol.VIII n.5 - October 1968
Mammillaria crispiseta
Referred to Mammillaria mystax