First of all, let’s consider a scenario that most people envision before eating a wild mushroom.

“Within 6 to 12 hours after consumption, violent abdominal pain, vomiting, and bloody diarrhea appear, causing rapid loss of fluid from the tissues and intense thirst,” warns Encyclopedia Britannica. Next, your liver, kidneys and central nervous system begin to fail, you lapse into a coma, and … well, you know the rest.

Big mistake: You’ve ingested an amanita phalloides, commonly known as a death cap mushroom.

Your body reacts pretty much the same way if you eat an autumn skullcap: diarrhea, vomiting, hypothermia, liver damage …

That’s why it’s a good idea to have an expert along when foraging for fungi in the forest.

Luckily, our small group of hikers that tramped through the Carter Preserve in Charlestown, R.I., one afternoon last week included mycological maven Maggie Jones, director emeritus of the Denison Pequotsepos Nature Center in Mystic.

“Wow! Check this out!” she exclaimed, making a beeline toward a wrinkled, gray mass near the base of a rotting oak tree that looked like something Igor might have exhumed for Frankenstein’s monster.

“Hen of the woods,” Maggie explained, carefully placing the mushroom in a plastic bag for consumption later. Along with its fungus cousin, chicken of the woods, hen of the woods makes for a sumptuous dish when sauteed in olive oil, seasoned with spices and topped with soy sauce.

Early fall is prime time for hunting mushrooms, and this year’s crop has been especially bountiful, thanks to abundant rainfall and warm temperatures.

Judging by the plethora of snapped-off stems we encountered, a lot of other mushroom hunters had the same idea and beat us to the harvest. No matter, Betsy and Bob Graham, Maggie and I were mainly out for a walk in the woods, and we enjoyed an eight-mile ramble through one of Rhode Island’s most gloriously diverse open spaces.

The Carter Preserve’s loop of four connected, well-marked trails wind through lush hardwood and evergreen groves, over sandy soil covered with pine needles, around glacial rocks, past an expansive wildflower meadow, among broad swaths of huckleberry bushes, and alongside a serene stretch of the Pawcatuck River.

Maggie noted that sections of the preserve “feel like a ghost town,” because gypsy moths have killed so many oak trees.

Still, “the understory of huckleberry and blueberry is thriving, along with pitch pine, sassafras and other sun-loving species,” she added.

Ironically, amid so much splendor, one of my favorite sections featured a much-maligned species: autumn olive.

This deciduous shrub, imported to the United States from Asia in the 1800s as an ornamental plant and then used widely in the 1950s for erosion control, spreads so rapidly that it crowds out many native species.

Autumn olives do possess one redeeming quality, though: tasty red berries.

“You guys go ahead — I’ll catch up,” I called over my shoulder, as I gobbled handful after handful of the sweet-sour fruit. I could just as well have feasted closer to home — autumn olive grows all over southeastern Connecticut.

We encountered a long row of the shrubs next to one of Rhode Island’s largest open grasslands, a 60-acre clearing that offers habitat for wildflowers and such shrub-nesting birds as grasshopper sparrows, prairie warblers, blue-winged warblers and American kestrels.

We spotted dozens of migrating dragonflies, monarchs and cloudless sulphur butterflies, darting and drifting over the grassland and adjacent shrublands that were bedecked with flowering goldenrods and asters.

“These late-blooming wildflowers, especially goldenrod species, offer pollen and nectar critical to bees, flies, wasps, butterflies, moths and other insects,” Maggie said.

The 1,100-acre Carter tract, The Nature Conservancy’s second largest nature preserve in Rhode Island, is part of an 11-mile corridor of contiguous forest and fields that had been farmed extensively during colonial times. Other neighboring properties include the Indian Cedar Swamp Management Area, Burlingame State Park and the Ninigret National Wildlife Area.

The Nature Conservancy established the Carter Preserve in 2001, with contributions from The Champlin Foundation, the Cove Point Foundation and the Doris Duke Charitable Foundation. It is named in honor of Francis “Frank” Carter, The Champlin Foundation’s former director.

Mushrooms and autumn olive berries may only be around for a few more weeks, but the preserve is worth visiting in any season.

Note: All visitors must wear a fluorescent orange hat or vest from Sept. 15 to Jan. 31, when bowhunting for deer is permitted on portions of the preserve.

There are two marked entrances to the preserve off Route 112, both with parking lots. One is south of Route 91 and a railroad bridge; the other is farther south, off Old Mill Road.

More information is available on The Nature Conservancy’s website, nature.org.