Many different kinds, including those from red onions (cipollotti rossi). Often they're called scalogni (shallots) because Italians use sprouted shallots as spring onions, too.
Cipollotti nocerini are a soft, delicate-flavoured variety grown since Roman times in the Sarno valley under the slopes of Mt. Vesuvius are popular in salads. Designated DOP.
Image by Guy Montag