Coryphantha cornifera (Rhinoceros Cactus)

Synonymes:Coryphantha radians, C.radians v.pectinoides, C.cornuta, C.schwarziana, C.maliterrarum, C.bernalensis
Distribution: Mexico - Hidalgo, Queretaro
Frost Tolerance: Hardy at least to -5 C
Habit: Globose
Encounterability in collections: Unusual in collections
C. radians and C. cornifera were regarded as two different species. But field studies show that the range of both is identical and at most locations adult plants either without central spines (formerly named radians), or with 1-4 central spines can be found.
With the exception of the abscence or existence of centrals all the other characteristics are absolutely identical, namely size and form of tubercles, number, size and arrangement of radial spines, flowers, fruits and seeds.
The areoles of the purely radial spined forms often are oval and of those with centrals round, a phenomenon which can be found in practically all those Coryphantha sp. which occur with and without centrals or which show a central-less youth-stage.

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