How to tell Booted knight from Fool's webcap
How they differ, how to recognize them and which is more dangerous — a mushroom comparison
Warning: Fool's webcap(Cortinarius orellanus)
DEADLY POISONOUS
Eating it can cause death. Do not pick it and do not taste it.
It contains orellanine (Cortinarius orellanus contains the highest concentrations among webcaps), as well as the related compounds orelline and orellinine. Orellanine is a nephrotoxin that destroys the cells of the kidneys' proximal tubules through oxidative stress. It accumulates in the kidneys and produces symptoms slowly.
Its unique feature is a record delay of symptoms: in a review of 90 described poisonings (Danel et al., 2001), digestive upset usually appeared on the third day and signs of kidney damage on the eighth or ninth, occasionally even later. Because of this delay: people don't link their worsening condition to a mushroom eaten a week earlier, by then several portions may already have been eaten, medical help comes late — when the kidneys are already badly damaged, activated charcoal and gastric lavage are no longer effective.
Clinical phases:
Phase 1 (from day 2, most often days 3-7): thirst, dry mouth, headache, nausea, lower back (kidney) pain, mild gastroenteritis. The symptoms are often written off as a cold or food poisoning.
Phase 2 (days 7-14): oliguria (reduced urination), then anuria (no urine at all). Rising creatinine and urea in the blood, hyperkalemia. This is the phase of full-blown acute kidney failure.
Phase 3 (day 14+): either recovery of kidney function (partial, with scarring), or progression to chronic kidney failure requiring lifelong hemodialysis or a kidney transplant.
Deaths have been described (for instance in a mass poisoning in Poland), but the more common outcome is chronic kidney failure: in the review by Danel et al. (2001) it developed in about half of the cases.
Treatment: there is NO specific antidote. Symptomatic: hemodialysis to remove toxins and support the kidneys, infusion therapy, electrolyte correction, and in severe cases a kidney transplant. The effectiveness of treatment depends critically on early detection — the sooner doctors start monitoring the kidneys, the sooner they can begin supportive treatment and dialysis. There is no specific treatment proven to limit the damage.
Prevention: no orange-russet gilled mushroom with a cobwebby cortina goes into the basket. NO EXCEPTIONS. It has no culinary value, and there are no similar edible species on a dangerous scale (the chanterelle has ridges instead of gills, honey fungus has a ring and paler gills).
If you suspect poisoning, call an ambulance immediately: 112 (the European emergency number) or your local emergency number
The short answer
Booted knight and Fool's webcap look alike, so they're easy to mix up — but Booted knight is conditionally edible, while Fool's webcap is deadly poisonous. The main visible difference: use: Booted knight — cook fresh, pickling, Fool's webcap — not eaten. The mushrooms also differ in the following features: cap color, cap surface, taste. If you have even the slightest doubt, leave the mushroom be.
Fool's webcap
Cortinarius orellanus
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Booted knight
Tricholoma focale
📊 Comparing characteristics
⚠ Highlighted rows are the key differences between the edible and the dangerous mushroom
| Characteristic | Fool's webcap | Booted knight |
|---|---|---|
| ⚠ Edibility class | Fool's webcap Deadly poisonous | Booted knight Conditionally edible |
| Season | Fool's webcap SummerAutumn | Booted knight SummerAutumn |
| ⚠ Use | Fool's webcap Not eaten | Booted knight Cook freshPickling |
| Size | Fool's webcap Medium (5–15 cm) | Booted knight Medium (5–15 cm) |
| ⚠ Cap color | Fool's webcap OrangeRedBrown | Booted knight OrangeBrown |
| Cap shape | Fool's webcap Convex | Booted knight Convex |
| ⚠ Cap surface | Fool's webcap Velvety | Booted knight Fibrous |
| ⚠ Taste | Fool's webcap Unknown | Booted knight Bitter |
| ⚠ Smell | Fool's webcap Odorless | Booted knight Floury |
| Flesh color change | Fool's webcap No change | Booted knight No change |
| Hymenophore | Fool's webcap Gilled | Booted knight Gilled |
| Stem | Fool's webcap Central | Booted knight Central |
| ⚠ Ring (veil) | Fool's webcap Ring remnants | Booted knight Ring present |
| Volva | Fool's webcap No volva | Booted knight No volva |
| Substrate | Fool's webcap Soil | Booted knight Soil |
| Nutrition type | Fool's webcap Mycorrhizal | Booted knight Mycorrhizal |
| ⚠ Partner trees | Fool's webcap OakBeechBirch | Booted knight PineSpruce |
📅 Seasonality
Fool's webcap
Fruiting season
August – October
Booted knight
Fruiting season
August – October
🔬 Morphology
Cap
Fool's webcap
Cap 3-8 cm across, hemispherical to conical-convex in young mushrooms, later becoming convex to flat with a low umbo. Color orange-red, fiery orange, russet-orange, darker in the center, paler at the margin. Surface velvety and dryish, microscopically scaly, not slimy. The cap margin is thin, with fine radial fibers in young mushrooms.
Booted knight
Cap 6-15 cm across, when young convex with an inrolled margin, becoming with age flattened-expanded. The skin is matte, with fine radial fibers. Color: orange-chestnut, ochre-orange, richer in the center, paler toward the margin; in old fruiting bodies, brownish-ochre with rusty spots. The margin is even, with remnants of the ring membrane when young.
Hymenophore
Fool's webcap
Gills — attached to the stem, widely spaced, broad. In young mushrooms russet-orange, darkening over time to rusty brown as the spore powder ripens. Spore print rusty brown — a diagnostic feature of the genus Cortinarius. In young mushrooms the gills are covered by a cobweb-like partial veil (cortina).
Booted knight
Gilled hymenophore — the gills are notched (sinuate) where they attach to the stem, crowded, fleshy. When young they are whitish, becoming with age creamy with rusty spots at the edges. Spore print white — diagnostic (it sets it apart from webcaps, which have a rusty-brown spore print).
Stem
Fool's webcap
Stem 4-9 cm tall, 0.7-1.5 cm thick, cylindrical, long, relatively slender, often thickening toward the base. Color yellow-orange to yellow, paler toward the base. The surface has fine lengthwise fibers. Remnants of the cobwebby cortina on the stem form a thin band with rusty-brown spores that have settled on the veil remnant.
Booted knight
Stem 5-10 cm tall, 1.5-3 cm thick, firm, fleshy, with a distinct membranous ring in the upper third — the main peculiarity for the genus Tricholoma. Color white above the ring, orange-ochre below, matching the cap color. Surface fibrous, scaly-fibrous below the ring.
Flesh
Fool's webcap
Flesh firm, orange-yellow to brownish yellow. When cut, it does not change color. Smell faint, neutral; in some populations with a hint of radish. Taste mild, indistinct (do NOT taste it — even a small amount of toxin is dangerous).
Booted knight
Flesh firm, fleshy, whitish, unchanging where cut. Smell distinctly mealy, taste mild at first, then bitterish-mealy, which disappears after boiling.
Smell
Fool's webcap
Faint and neutral, with no distinctive notes. The smell is NOT a warning sign — the mushroom smells neutral, which makes it even more treacherous.
Booted knight
A distinct mealy smell — a diagnostic feature of the genus, especially clear when cut and in young specimens.
📍 Habitats
Fool's webcap
Booted knight
👀 Similar mushrooms — don't mix them up!
❓ Frequently asked questions
Can Booted knight and Fool's webcap be mixed up?
How to tell Booted knight from Fool's webcap?
Which is more dangerous — Booted knight or Fool's webcap?
Is Fool's webcap edible?
When do Booted knight and Fool's webcap grow?
Sources
- [1]Вікіпедія (українська)
- [2]Атлас грибів України, Зеров Д.К. (1979)
- [3]MycoBank Database
- [4]Index Fungorum
- [5]GBIF
- [6]iNaturalist Ukraine