Webcap

Where it grows

Cortinarius is the largest genus of mushrooms in Europe, with thousands of species fruiting in summer and autumn in mycorrhizal association with broadleaf and coniferous trees. Webcaps are found in every forest soil and represent some of the most identification-challenging fungi on earth.

How to recognise it

The defining feature of the genus is the cortina — a cobwebby partial veil between the cap and stem in young specimens — which collapses with age, leaving fibrous remnants on the stem and a rusty-brown ring stain where falling spores caught on it. The mature gills and spore print are an unmistakable rusty brown.

Edibility & cautions

Treat the entire genus as potentially dangerous. Several Cortinarius species (including the Deadly Webcap and the Fool’s Webcap) contain the slow-acting toxin orellanine, which silently destroys the kidneys over days or weeks before any symptoms appear. By the time thirst, lower-back pain, and reduced urination set in, irreversible kidney failure may already have occurred and a transplant may be needed. Because identification within the genus is so difficult even for experts, the safest rule for beginners is simple: any mushroom with a cobwebby veil and a rusty-brown spore print is to be admired and left alone.