This fall, as usual, Steve Brill has been cruising New York City neighborhoods for groceries. And he has come across quite a few specials: poor man's pepper, purslane, lamb's quarters, wild grapes, black walnuts, [common evening] primrose root, goutweed, burdock root, epazote and at least one hen-of-the-wood mushroom.

"Enough food for a week's worth of incredibly delicious meals," said Mr. Brill, who forages-legally-for all-organic food in parks throughout the five boroughs.

This is not a new exercise for Mr. Brill, known as Wildman to his friends and students and the countless children who, for almost a decade, have traipsed with him through New York's greenswards in search of berries, roots, fruit, blossoms, herbs, nuts, mushrooms, leaves and other often amazingly savory wild edibles. He collects only from pollution-free and pesticide-free sources and always leaves enough plant life for future reproduction.

Safety is paramount for Mr. Brill, who seems personally offended by misinformation, like the skunk cabbage reports he has read recently.

"No matter what you read elsewhere, skunk cabbage is not edible, regardless of how long you dry it," he said with the kind of authority that brooks no objection.

What began as a hobby for a vegetarian who wanted to eat better, feel better and spend less became a full-time profession in 1986 when Mr. Brill was arrested green in Central Park. (The arresting officers were working undercover, posing as foragers themselves.) The charges were later dropped, and a contrite Henry J. Stern, the Parks Commissioner, hired him as a naturalist in the city's park system, a position he held from 1986 to 1990.

Trim and vigorous at 46, the bearded and balding Wildman lives and entertains frugally, supplementing foraged food with tofu and health-food-store products. As a freelance naturalist, he leads wild food and ecology tours in and around New York, does radio shows on the environment on WBAI-FM, and continues to amass information on the growing conditions and potential health benefits of wild foods.

Mr. Brill's book, "Identifying and Harvesting Edible and Medicinal Plants in Wild (and Not So Wild) Places" (Hearst Books, $17.95), is a veritable road map to the edible outdoors. "The title could put you to sleep, couldn't it?" asked the author, who added that his publisher was responsible for naming the result of his five years of botanical and nutritional research. "There's a lot of excitement inside, though."

In the book, he chronicles 500 plants in fond scientific, historic and culinary detail. For example, he writes, tea made from mullein leaves and flowers quiets a cough. The steamed leaves of stinging nettles are a superb vegetable. Protein-rich cattail stalk tastes like corn. And the supply of epazote, the resinous herb prized in Mexican cooking, is plentiful.

Instead of being listed by botanical groups, the wild edibles are arranged by season and by habitat (seashore, marshes, lawns, meadows and so on), making it easier for foragers nationwide to find them.

There are no potentially misleading photographs, which show only one moment in a plant's life. Instead the illustrator, Evelyn Dean, has provided precise and annotated black-and-white line drawings of each plant. Poisonous look-alikes and plants "for observation only" are described in detail. For readers, there should be no mistaken identities.

Foraging has apparently gone mainstream: Mr. Brill says he is getting more calls from chefs and restaurateurs seeking exotica, as well as from people who just realized that those hen-of-the-woods mushrooms they have been paying premium prices for are growing in their own backyards.

"Suddenly, everybody wants to be out picking," Mr. Brill said. "And that's a good thing, because the more people realize how beautiful and powerful the food supply is, the more they will care about the total environment."

On weekends and holidays from March to December, Mr. Brill leads groups on food forays to Manhattan, Long Island, Connecticut and Bear Mountain, NY. A schedule can be obtained by writing to him at 143-25 84th Drive, Suite 6C, Jamaica, NY 11435 (enclose a self-addressed stamped envelope) or by calling (718) 291-6825.

For public tours, Mr. Brill asks for a small donation, if possible. For private tours, like for groups of schoolchildren, a fee is arranged.