After doing a little research, I can state with certainty that those were not top-setting onions, because top-setting onions never produce flowers. That's because the purpose of a flower is to produce seed, and top-setting onions don't set seed, either. If you can't find your top-setting onions, it may be because (according to Mother Earth News) they don't produce underground bulbs, so if you harvested the bulbils last fall, that's all you have left of last years' plants. My guess is that they are chives, because it's the right time of year for chives to begin blooming. At the nursery I work in, all the onions and scallions are still tiny little grassy-looking things, and we don't even have shallots and leeks yet.

I should have realized that, as the bloom looks nothing like the walking onions I have. The part that puzzles me, is I don't remember putting anything in those pots except the bulbils from the tops of the topsetting onion. I MUST be losing my mind. I'm going to have to talk to my husband and look again in the bed where the main plant has been. It's behind as very large plant right now... if it's still there. The main plant has been there for a LONG time.

Thanks for the info. Today was great! Thank you for all the wonderful plants!