Lethal Webcaps

The cap is the clearest starting point for identification: conical to convex, 2.5 to 8 centimeters across, tawny to date brown with paler margins and covered in fine, fibrous scales. With maturity the cap can flatten and develop a central bump, or umbo.

The gills are ochre or caramel-colored when young, deepening to a darker brown as the spores mature. They attach to the stipe in an adnate fashion. The stipe itself stands 5.5 to 11 centimeters tall and 0.5 to 1.5 centimeters thick, with a bulbous base, colored the same as the cap or slightly paler, and sometimes carrying yellow fragments of the cortina veil on its lower half.

The flesh is cream to pale yellow, turning more tan beneath the cap surface and in the stem base. It gives off a slight smell of radishes and has no strong taste.

Cortinarius rubellus occurs in high-latitude temperate to subalpine forests across the northern hemisphere. It has been recorded in subalpine conifer forest in the Yatsugatake Mountains of Yamanashi Prefecture in central Japan, and in North America it is known from British Columbia and western Washington, including Mount Rainier National Park.

In Europe it occurs in Scandinavia and in the north of the British Isles, where it favors wet areas within conifer or mixed conifer and broadleaf woodlands, though it remains uncommon there.

Across its range the species appears tied to cooler, higher-elevation forest conditions rather than lowland or warmer habitats.

The mushroom holds no positive associations in folklore or traditional medicine; its cultural significance instead centers on danger and its influence on public health awareness.

In September 2008, author Nicholas Evans, his wife Charlotte Gordon Cumming, and two relatives were poisoned after gathering the mushrooms on holiday, having mistaken them for ceps and overlooking their gills. All four were told they would eventually need kidney transplants; Evans later received a kidney from his daughter, and the others received transplants after searching for donors. Charlotte had eaten only three mouthfuls. The group went on to help found the charity Give a Kidney.

1. Within its genus, Cortinarius rubellus belongs to a small group called the Orellani, all of which are highly toxic.
2. Cortinarius orellanus and C. rubellus together make up the two best-known deadly webcaps found across Europe and North America.
3. The mushroom has become something of a cautionary tale in foraging communities and academic circles, cited repeatedly as an example of how toxic and edible species can be confused.