What's wrong with this beautiful cactus?

[fanaticactus]

Difference is oyygona produces normal length spines on the mature areoles whereas eyriesii mature areoles are short spined or almost spineless. If you note the new offsets on both are virtually the same being spiny, but on eyriesii the spines get shorter or often disappear as the offset gets older. Evidently both forms can be found growing together in the same population in habitat.

See page 27 of this link:-

http://www.cactusexplorers.org.uk/Explo ... mplete.pdf

So it really is a fairly subtle difference. Thanks for the explanation.