This week's look at what's bountiful, new or even mysterious in the produce aisle.

There once was a time--before the arrival of mesclun, frisee, endive, spring mix, packaged salads, radicchio and arugula--when iceberg lettuce dominated the produce aisle. Quartered, shredded, its leaves pulled off and transformed into cups for canned pears, it knew no rival until the 1970s when Cesar Chavez called for a boycott to protest the working conditions of California lettuce pickers. Tastes changed, too. The wedge of iceberg drowning in a thick dressing was replaced with vinaigrette-tossed leaf lettuces (especially romaine) and smaller, more exotic "designer" greens, all more nutritional and more flavorful than the "neutral" iceberg.

Iceberg--a head lettuce, as opposed to a leaf lettuce--is also known as "crisphead" lettuce since one of its chief virtues (some say its only virtue) is that it stays fresher longer than leaf lettuces.

It is very firm and, when cut open, shows a highly compact structure with ribs inside. Most iceberg in your supermarket comes from California's sandy, loamy soil. As summer heats up and other lettuces--all cool weather crops--begin to fade, iceberg gains some in popularity simply because it stays crisp in the heat and travels well if you're taking food on picnics.

What to look for: Giant Food's produce maestro, Charlie Lester, recommends choosing firm, densely packed heads with no brown spots. If wrapped in plastic in your refrigerator's vegetable bin, a head of iceberg can last from two to three weeks. In addition, he advises that iceberg lettuce should be separated from oranges and apples. When they are side by side in the vegetable bin, the ethylene gas from the fruit can turn lettuce brown.

How to prepare: Iceberg stays fresher if its core is removed. First, tear off any loose leaves on the outside of the head. Then with a small sharp knife, cut about two inches deep around the head's tough white core and remove it. Many people like the head cut into wedges for a salad, and it holds up well under creamy dressings, such as blue cheese, poppy seed or ranch. When torn in small pieces, it mixes well with other, more nutritional and flavorful greens, and can give a loose-leaf salad a crisp infrastructure. Many of us may have forgotten why iceberg lettuce is the perfect "L" in any BLT. It stays crisp and crunchy, even when layered between warm toast and hot bacon. Same for club sandwiches. Shredded, it is essential in tacos. Whole leaves make a nice "cup" for crab, shrimp or tuna salads or fruit salads and their juices.