Dr. Charles Allen, a Louisiana botanist, cut off what looked like a large, flowering weed near a lagoon in Audubon Park. Ordinarily, this would be a lawn mower victim, or at best part of a wild bouquet.

Allen had other ideas.

“You can take the white flowers and put them in pancake batter,” Allen said of the elderberry plant, one of a variety of wild edibles that grow in the park.

“Or you can add it to bread,” he continued. “It’s delicious. And later, you can take the berries and add them to your wine.”

A group of about 20 men and women looked on. Some took notes, sketching the plants that Allen showed them and noting tips for identifying them on future foraging expeditions. Others inhaled deeply, smelling the flowers. A few grabbed some stems and stashed them in cloth bags to take home.

For most so-called “locavores” — people who want to eat only locally produced food — eating foods that come from within a certain radius will do. Allen’s walking tour suggested that some forms of sustenance might be sprouting more or less under our feet.

It was one of three events hosted over the weekend as part of the New Orleans Eat Local Challenge. Sponsored by companies including Rouses Markets, Hollygrove Market & Farm and Good Eggs NOLA, the campaign challenges New Orleanians to eat only food grown, caught or raised within 200 miles of New Orleans for 30 days.

“All these plants used for spices, teas and food are what we now usually spray with weed killer,” said Lee Stafford, a co-founder of the Eat Local challenge, which started in 2011. “But in the past five years there’s been a growing trend to put these plants on local menus.”

Weeds and flowers made up just a portion of the local menu during this year’s challenge.

Chef Zack Lemann of the Audubon Insectarium offered insect tasting at the “Hop and Fly, Heat and Fry Event,” a cooking demo earlier this month. New Orleans’ self-proclaimed “premier bug chef” also led a field trip to the Manchac area to catch dragonflies and grasshoppers for the dinner table.

The restaurant Carmo hosted a “trash fish” happy hour, serving Gulf seafood that rarely makes it onto local menus.

Stafford said the overarching goal is not just to support local food providers but to improve local diets, adding nutrients, enzymes and antioxidants that are missing from the typical American diet of transported fruits and vegetables and processed breads and meats.

“We are breeding the nutrition out of our foods,” Stafford said. “But the more we diversify our diet, the more we’ll get a wider range of vitamins and minerals.”

Allen, the author of “The Edible Plants of the Gulf South” and other books about plant life in Louisiana, spoke directly to that message during Saturday’s foraging trip.

“We’d all be a lot healthier if we ate things produced within a few miles of where we live,” he said. “You don’t get as many allergies, for example.”

Allen said most of the plants he pointed out are dismissed as weeds, yet at one point they fed entire populations of Native Americans, who relied on them for regular meals.

For example, peppergrass, or “poor man’s pepper,” tastes like horseradish and can be used to spice pretty much any dish, while bull briars, a spiky plant that grows near water, is a form of wild asparagus that can be cooked and served as a side dish.

Even black cherry can be used to make cocktails, he said, and is particularly good in chilled vodka.

“Lots of people spend lots of money to get these out of their lawn, but it’s edible,” Allen said, holding up another plant, nicknamed the “dollar weed,” that is a member of the carrot family. “Instead of spraying it you could just eat it.”

Although few of those who foraged with Allen on Saturday evening were participating in the Eat Local challenge, several said they had taken up an interest in foraging and eating local wildlife as a way to stay healthy.

Among them was Janet Opdenhoff, a horticulturist and massage therapist who had traveled more than three hours from Pineville to forage in Audubon Park.

“I’m really into edible plants and medicinal plants these days,” Opdenhoff said, adding that she was hoping to garden some of the plants she had learned about during the trip. “It makes me feel like I’m taking an active role in my health, rather than just going to the doctor or taking a pill.”

Others, like 22-year-old Isa Vizcarra, attended because it was an easy, fun and cheap event near where she worked. After the event was over, Vizcarra said she had found a new appreciation for Audubon Park, where she already spends a lot of her time.

“This is my park, you know?” Vizcarra said as she smelled the elderberry. “I know every area of this park, except what plants I can eat. And now I’ll know that, too.”