Morchella eximia

Overview

Morchella eximia is a true morel, known as the black morel. The catalogue records it as wild-harvested and as cultivated in managed beds, with regional records in Patagonia, China and other temperate regions. Its name is treated inconsistently: some sources use Morchella septimelata for the same concept.

A 2023 outbreak

In March and April 2023, 51 people who ate at a restaurant in Bozeman, Montana, developed mild to severe gastrointestinal illness, and two died. Symptoms began quickly, with a median onset of about one hour after the meal. Sequencing identified the mushroom as "Morchella sextelata", described as a species of true morel; that spelling is the report's own.

Investigators judged uncooked or undercooked morels the likely source. A case-control study found that eating raw morels was more strongly associated with illness than eating cooked or partly cooked ones. No specific toxin was confirmed, and the report notes that morel toxins are not well characterized.

Preparation and precaution

The CDC report advises cooking morels before eating, because cooking is likely to reduce toxin levels. It describes proper preparation, including thorough cooking, as something that might limit adverse effects. It does not describe cooking as a guarantee of safety.

Morels should not be eaten raw or undercooked. The catalogue also notes that morphology alone may not settle the species.

Names and records

The catalogue's regional records are Patagonia, China and other temperate regions, and it lists both wild harvest and cultivation, with a regional trade in the dried product. The Morchella septimelata treatment is recorded as an alternative taxonomic view, not as a settled synonym.