"Arugula!" a colleague cried excitedly. "It's still growing, and how much better it is in winter!"

"Arugula?" I wondered. A search among garden books, old and new catalogues and other gardening friends revealed little. I learned that it was a salad green and that it was peppery and sought after in specialty grocery stores. But still no information as to its origin or culture.

The excited colleague finally broke the code. "It's also known as roquette," he confessed.

Roquette I know about. It's pronounced rock-ette, spelled rocket, roquette, rugula or arugula. The French claim it as a native, and so do the Italians. It's loved for the tangy taste it adds to a salad, and often equally disliked. The leaf, which is the only part you eat, looks like that of a dandelion.

The Burpee catalogue carries it with the following description: "Roquette (Rocket, Rugula); 35 days. Tender, young leaves with robust, peppery flavor -- a pleasant accent to tossed salads. Cook mature leaves with other greens. Easy to grow for spring or fall crop; pull plants in summer before they bolt to prevent self-sowing. Very popular in Europe."

The New York Times Book of Vegetable Gardening says of roquette: "It has a distinct, sharp flavor that should be mixed with other salad greens. Sow in spring or fall, as it is not a hot-weather grower."

Dr. Bernie Doll has grown arugula in his Washington garden for five years. "I'd known about it from friends who bought it in specialty grocery stores. I'd been to France so I was interested in it. I found a place in Topeka, Kansas, of all places, that carries imported French seeds. So I sent away for some.

"It's easy to grow. It reseeds itself very nicely in the fall. You can sow it very early in the spring. It doesn't mind frost orreally cold weather.

"Mine is still growing. I don't remember it ever growing this far into winter. But you have to be careful about eating it in the summer -- it gets pretty hot."

A casual survey of gourmets who are fond of arugula revealed that none had eaten it cooked, as Burpee suggests. All raved about its virtues as a salad green either mixed with other lettuce or by itself. One gardener had enjoyed it served in a restaurant "with tomatoes and capers."

I've seen seed packages of roquette at garden stores but I've never seen it sold as arugula. Although it's available through Burpee, I haven't found it in Park's, and I'm only just receiving other catalogues. Thus far, Burpee's and Dr. Doll's Topeka source are the only two places I've found that definitely carry roquette. ARUGULA BY ANY NAME: For information on arugula, roquette or rocket seeds, write: BURPEE GARDENS, W. Atlee Burpee Co., 300 Park Avenue, Warminster, Pennsylvania 18991. J.A.DEMONCHAUX, 827 North Kansas, Topeka, Kansas 66608.