Ornamental garlic

It's an allium of some sort and it came home from the farmers' market in a pot of something else. The leaves are droopy and there the year 'round. It has seeded since into two other pots. The odd thing is that they never bloom concurrently. The original pot always blooms second and one of the offspring pots blooms before the original and one blooms after it. The flowers last a good long time.