I just noted the posting by @Terry Phillips of Eriosyce esmeraldana at Appreciation: - Eriosyce esmeraldana, and now I wonder if that's the name of my cactus. I was given this plant almost 20 years ago, only recently thought of wanting to know what it was, when I saw another posting about a misshapen cactus and wondered if this was supposed to have a globular shape. It's at a window but next to my computer, so I keep the blinds turned to keep the sun off the computer. It has flowered, though not for the past several years, when I've kept the blinds more closed than previously. Flowers were pale yellow, if I remember correctly, not a sure thing.