In my house, foraging is a favorite family pastime. So I was delighted when my husband called to tell me he had a foraged surprise for me. I came home to a beautiful basket of nuts. He smiled sweetly when he told me he had come across a cluster of chestnuts.

I looked at him quizzically, wondering how in the world he found such a special and rare tree that I hadn’t ever observed on the Island. Then I looked at the gift, jumped on the computer to confirm my suspicions, and smiled back just as sweetly.

Are you trying to kill us both, I asked?

American Chestnut trees, though once ubiquitous, were felled by a fungus that decimated their population in the 20th century. A few other varieties of chestnut trees (genus Castanea) can be found nationwide, but I could uncover no records of them here on the Island. Efforts are underway to restore the population of American chestnut trees across their former range, including in Massachusetts, though I don’t think they will be coming to the Vineyard anytime soon.

What my husband had found and foraged was horse chestnuts, a very different tree with a similar look, if a very different edibility. Hailing from the genus Aesculus, this tree was truly a horse of a different color, and one that could cause harm, and even death if consumed.

Horse chestnuts are a commonly planted in cities, neighborhoods, parks and other planned landscapes, one of the many distinctions between it and the edible chestnut trees. American chestnuts are found in woods, forests and orchards, so location can be a clue as to which tree is which.

There are many other differences that can be observed. First the leaves. True chestnut trees have each leaf attached at separate points on the stem, while the horse chestnut, also called buckeye, has five or six leaves attached a one point. Next, look at the husk or bur. Members of the Castanea genus have a spiny husk, while the buckeye has a fleshy, bumpy husk with a warty appearance.

I shared pictures of both plants with my husband, who, upon reflection, suspected that he had buckeyes or conkers, the nuts of the horse chestnut tree. Looking at the nuts on the counter, the differences were clear.

Chestnuts have two to three nuts per burr, while buckeyes have usually only one. The tail end of the nuts differs also, with the chestnut having a pointed tip or tail on the bottom and the buckeye being rounded and even indented at the bottom. My foraged gifts were definitely not chestnuts.

The good news is that we were spared the illness that the misidentification could have caused. Consumption of raw buckeyes causes sickness and death in a variety of species, including humans. Dogs, cats, horses, pigs, cattle, sheep and chickens can be poisoned and honeybees can be killed if they drink the nectar or sap of certain varieties of horse chestnuts. Symptoms in all creatures can include gastrointestinal upset, kidney and liver damage, weakness, vomiting, paralysis and death. Interestingly, deer can and do consume conkers with no ill effects.

Confusion among edible plants is common and this specific mix up even more so. In a study in France of calls to Poison Control Centers, more than 10 per cent of confusions between plant species were attributed to the buckeye/chestnut misidentifications. The U.S. FDA labels horse chestnut an unsafe herb.

The basket of buckeyes will be put outside for the wildlife and I will take heart that my sweetheart didn’t have a death wish for him or me. I will also be cautious the next time he tells me he has a special surprise. 

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.