First things first, let’s do the name thing.
It’s radicchio as in Rick, not rich. The ‘CH’ is pronounced ‘CK’ (as the famous cologne); so ra-dee-ckyoh.
Radicchio is one of those foods I think of as very grown up.
It has moustaches, monocles and wanders around the apartment in a regimental dressing gown, with the New Yorker tucked under his arm, smoking a pipe and sipping bourbon.
Radicchio is upscale and sophisticated and looks down with contempt at the dull plebeian lettuce murmuring “We are not cut from the same cloth!”
In a way, snobbish radicchio has the right to say so because it is not, strictly speaking, a variety of lettuce.
It’s a member of the chicory family that comes in several varieties, with two types being most widely available in the United States: Treviso and Chioggia. Treviso leaves are oblong with pointed ends and grow in small, tightly packed heads. Chioggia instead grown in loosely packed round heads similar in shape to lettuce. Both varieties have purple leaves with white ribs.