Nodding onion is a native perennial widespread across much of North America, only absent in a few states. It is a type of onion, so there is a bulb with green stems and beautiful flowers. They will grow in deciduous woodlands and grasslands, giving you a variety of places to put them in a garden.
Despite it’s small size, nodding onion does contribute to the environment. There are even two caterpillars that consider it a host plant, Yellow-Striped Armyworm (Spodoptera ornithogalli), and Schinia rosea (no common name found). It is also important for many native bees as well as animals that eat the leaves.
Nodding onions look somewhat like the invasive wild onion Allium vineale, so make sure not to plant the invasive in a garden, but you can certainly harvest it wild and eat it. Why settlers felt the need to bring onions from Europe when we have so many great ones, I do not know, but they are here for good.
Some advice that I read is that they can be confused with deathcamas, a group of plants that look somewhat similar to onions, though lack the distinctive smell. As the name implied, deathcamas should never be eaten. That said, looking at pictures of them, I don’t think I would confuse them with onions, but just make sure you don’t.
Map Source:
USDA Plants Profile
Photo Credit:
https://commons.wikimedia.org/w/index.php?curid=9486431