Escarole is a member of the curly leaved and slightly bitter tasting plant family that has several members. It is used mainly in salads, and can also be braised. It has firm, broad, dark almost gray-green leaves with a little cream showing in the ribs.

Escarole is low in calories, high in anti-oxidants and vitamin A, is high in fiber and each cup is worth a whopping 10 calories-real diet food. Escarole is like most greens and is available year round. Select greens that have no brown spots, or yellowed leaves. The leaves should be crisp, dark green, and the core should be a creamy white. Heads should be full. One head yields four servings. 

To store greens, rinse in luke warm water, shake or pat dry and keep in plastic bags or covered with plastic to reduce evaporation. Escarole stores for up to one week at 38 degrees F.

Here is a very good site for Escarole information:
http://www.orst.edu/Dept/NWREC/endive.html