What is the single most important safety precaution related to identifying true *Allium* species when harvesting greens from the wild?

Crushing a part of the plant to check if it emits a characteristic onion or garlic smell.

When venturing outside of cultivated environments to forage for greens that resemble onions, identification requires extreme certainty due to the presence of extremely dangerous imposters in the wild, such as deadly poison hemlock or death camas. The single most critical safety precaution relies on olfactory identification. True species belonging to the *Allium* family, encompassing wild onions and their relatives, will always emit a distinct and characteristic odor—either onion or garlic—when their leaves or bulbs are crushed or bruised. If this characteristic scent is absent upon crushing, the plant must be avoided entirely, as toxic look-alikes do not share this pungent quality.