American yellow morel

What it is

The American yellow morel is a true morel, a spring mushroom with a honeycomb-like cap and a hollow stem. The Michigan Department of Natural Resources lists it among the easiest spring mushrooms to recognize, and the honeycomb cap with a hollow stem is the key feature that separates it from the false morels.

The name is not settled. Some sources use Morchella americana and others use Morchella esculentoides, a name that was split from the European Morchella esculenta. Some sources also describe a grey morel, which may be young American yellow morels.

How it is eaten

Morels are cooked rather than eaten raw. Sources describe sauteing, grilling and roasting, rolling sliced morels in a buttermilk and cornmeal batter for pan frying, and cooking them with onion, pepper and butter into a cream gravy. One source says they can occasionally be eaten raw; the outbreak evidence below points the other way.

The Michigan DNR says all wild mushrooms should be cleaned and thoroughly cooked before eating. Slicing a morel lengthwise shows whether insects are inside.

The 2023 outbreak

In March and April 2023, 51 people reported gastrointestinal illness after eating at one restaurant in Bozeman, Montana. Of these, 46 were patrons and 5 were employees. Two people died, three were hospitalized and four visited an emergency department.

DNA sequencing identified the mushroom as Morchella sextelata, a true morel. A case-control study linked the illness to a sushi roll that contained salmon and morels. Illness was more strongly associated with raw morels than with cooked or partially cooked ones, and the association followed a dose-response pattern. The report does not identify the toxin, and it says morel toxins are not well characterized.

Safety and identification

The CDC report says: "Morel mushrooms should be cooked before eating to mitigate potential toxic effects." It also says cooking is likely to reduce toxin levels, but it does not claim that cooking makes morels absolutely safe.

The main identification risk is confusing true morels with false morels in the genera Verpa and Gyromitra. The Michigan DNR says the easiest test is whether the cap attaches to the stalk, and that free-hanging caps should not be eaten. Cooking does not make false morels safe. The Michigan DNR also warns of stomach upset from the black morel, Morchella angusticeps, especially in large amounts or with alcohol; that warning concerns the black morel, not this species.

Nothing on this page identifies a specimen. A wild morel should be checked by an experienced local forager or a field guide before it is eaten.