Radicchio is a red, broadleaf, heading form of chicory.
Some cultivars form loose heads, while others have folded leaves and resemble small cabbages.
Leaf texture is similar to but stockier than that of a French endive. The red coloration increases during the colder months. The first growth of many radicchios is green. The green leaves are tough and very bitter. If these leaves are cut back in fall and the winter is cold, the second growth will be bright red or magenta.