Winter Onions are perennial onions that produce many seeds or bulbils that take root in the spring and yield delicious green onions in the early spring. The name can apply to any of several perennial onions. This one is likely Allium cepa proliferum, also called Egyptian Onion, Tree Onion, and Walking Onion, which forms tiny bulbs (bulbils) at the tops of leaves. Its tendency to spread around the garden accounts for the name Wild Walking Onion.