The common name scallion is associated with various members of the genus Allium that lack a fully-developed bulb. They tend to be milder tasting than other onions and are typically used raw in salads.
Scallions are also known as green onions in the U.S. and spring onions in the UK and Australia. In Scotland, they are commonly referred to as 'Cibies'. Confusingly, the term "green onion" can also be used for immature specimens of the ordinary onion Allium cepa.
The species most commonly associated with the name is the welsh onion, Allium fistulosum. The name can also be used for Allium ascalonicum, better known as the shallot. The words "scallion" and "shallot" are related and can be traced back to the Greek askolonion.
This article is based on an original article at Wikipedia. You can find a copy of the original at http://en.wikipedia.org/wiki/Scallion.