green onion

green onion, young onions (family Amaryllidaceae) harvested when their tops are green and the underdeveloped bulbs are 13 mm (0.5 inch) or less in diameter. Many commercial green onions are immature plants of the common onion (Allium cepa), but the Chinese onion (A. chinense) and the Welsh onion (A. fistulosum), both from Asia, and hybrids of A. cepa and A. fistulosum are also common. Their flavour is mild, and nearly the entire onion, including the hollow tubular tops, stem, and bulb, is used raw in salads and sauces, as a garnish, and as a seasoning for prepared dishes; green onions also can be pickled.

Green onions are closely related to chives (A. schoenoprasum), leeks (A. porrum), shallots (A. cepa, variety aggregatum), and garlic (A. sativum).