Allium fistulosum, the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant often considered to be a kind of scallion. The common name “Welsh onion” does not refer to Wales but derives from a near obsolete use of Welsh in the sense “foreign, non-native,” as the species is actually native to China.
Welsh onions are very similar in taste and odor to the related common onion, Allium cepa. The Welsh onion, however, does not develop bulbs, and possesses hollow leaves (fistulosum means “hollow”) and scapes. Larger varieties, such as the Japanese negi, resemble leeks, whilst smaller varieties resemble chives. Allium fistulosum can multiply by forming perennial evergreen clumps.
The Japanese name is negi (葱), which can also refer to other plants of the genus or, more specifically, naganegi (長葱), meaning “long onion.” It is used in miso soup, negimaki (beef and scallion rolls), among other dishes, and it is widely sliced up and used as a garnish.
