Radicchio, a member of the Cichorium genus, possesses a slightly bitter flavor when eaten raw. Red radicchio is a variety of red chicorium and is considered by many to be the quintessential Italian lettuce.
Italy is the largest producer of radicchio, with southern France being the second largest. There are two varieties most commonly available in the United States: radicchio di Verona and radicchio di Treviso.
Radicchio di Verona has burgundy red leaves and white ribs. Similar to butterhead lettuce, it grows in small, loose heads. Radicchio di Treviso, however, has leaves that are narrow and pointed similar to Belgium endive. Here the leaves form upright, semi-open heads of long, straight ribs with leaves that vary in color from pink to dark red.
All radicchios have tender yet firm leaves with a slightly bitter flavor. They are generally available year-round, but thrive in the fall and spring seasons. With a variety of uses in salads, grilled, sauteed, or baked, radicchio lends both versatility and flavor to a variety of dishes.