It looks impressive, but what is it? At first I thought it might be a Neoporteria senilis (Eriosyce senilis), but I have a feeling that it is too large for that: it has a diameter of 10 cm and a height of 6 cm. It certainly has the nestlike spine structure of an Eriosyce nudus (another alternative name) and, while almost all of the spines are white, a few are brownish-black.If anyone can help identifying this cactus, I would be most grateful.
