According to Dicht and Luty, C,. ottinis is described as solitary, globose to short cylindrical, axils woolly with glands, aeoles round, white woolly in youth, radial spines 8-12, th eupper ones somewhat thinner, 9-11mm long, central spines 1-3, rarely 4, the lower sometimes curved downwards, upper ones (2-3) pointing upward.
In the comments, they say that southeast of the distribution area (Puebla, Tlaxcala, Mexico, Hidalgo) forms with sparser spination and only 1-2 central spines can be found.
So what is "normal"?
Normal to me just means the popualtion of plants from which the species was first collected, and thereby introduced into cultivation. In my experience, "normal" is not what you find in habitat - where you find all kinds of variations.
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Chris43, moderator