When I purchased one of my cacti in mid-December (not identified yet), I noticed that it had some buds on its sides. I've never seen cactus flowers or buds, but that's what they seemed to be, instinctively. I left for a holiday soon after, and when I returned in January, some of the buds had shrivelled and retracted, while some were still poking out.
To this day, some of these growths are still hanging on the plants, but I've never seen any flowers on it.
What are these growths?