shallot Allium cepa, Aggregatum Group, differs from the regular onion in that instead of having a single bulb it divides into a cluster of small bulbs. These are smaller, more delicate in flavour, and less powerful in smell than round onions.
This subdivision is a characteristic which the shallot shares with some other species, all of which are known as aggregate or bunching onions. Some sorts, milder than shallots, are usually called ‘multiplier’ or ‘ever ready’ onions. One, grown mainly in Ireland, is the ‘potato onion’, so called because its bulbs are broader than they are high.