I'd like to know what this one is just in case it has any special care requirements. I can see what I think are the 'tells' for the genus (the symmetrical curved-back radial spines, the long central spine, the areole shape and the way the areole seems almost pulled out from the ribs), but I can't translate that into a name.
No top view because there's nothing to look at. The cactus unfolds smoothly from within with only a naked areole to break the clean lines.
