Torn fibrecap Inosperma rimosum
poisonousStraw-yellow to yellow-brown, conical, bumped and cracked cap; the flesh does not turn red. Also poisonous because of muscarine.
Identification in 5 steps
Inosperma erubescens is a fibrous fibrecap whose flesh stains red-brown where damaged. It is poisonous and must not be mistaken for the edible St. George's mushroom.
SeasonMay to September
Spore printbrown
FamilyInocybaceae
- Cap. The cap is 3 to 8 cm wide, cream to yellowish, radially cracked.
- Underside. The gills are grey to brown.
- Stem, ring and volva. The stem is slender and fibrous, with no ring and no volva.
- Smell and taste. The smell is unpleasant to spermatic. Never taste it.
- Flesh and colour change. The flesh is cream and stains red-brown.
Lookalikes
A fibrecap with patches that turn red-brown; it can contain muscarine and is mistaken for St. George's mushroom.
White fibrecap Inocybe geophylla
poisonousSmall, pure white and silky glossy, spermatic smell; does not turn red. Also poisonous because of muscarine.
St. George's mushroom Calocybe gambosa
edible
Mealy smell, white spore print, edible.
View on the mapSide by side
| Deadly fibrecap | Torn fibrecap | White fibrecap | St. George's mushroom | |
|---|---|---|---|---|
| Cap | cream, cracked | yellow-brown, conical, cracked | white, silky, small | whitish, smooth |
| Underside | grey gills | grey-brown gills | grey-brown gills | whitish gills |
| Stem | fibrous | fibrous, does not redden | slender, white | whitish |
| Flesh | flesh cream, stains red-brown | fibrous, does not redden | fragile, does not redden | firm, smell of meal |
| Edibility | Poisonous | poisonous | poisonous | edible |
Habitat & Season
Humus-rich soils. Lowlands to low mountain ranges.
Host trees
Deciduous trees in parks and woods.
Season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
possible good main season
Early summer to autumn.
Mushroom regions with a daily forecast
There are no records per region for this species yet. The country pages lead to all regions with a daily forecast.
Safety
Never eat a mushroom you have not identified with certainty. Poisonous mushroom: do not eat it. If you suspect someone has eaten it, call the emergency number and the poison centre immediately.
Advice for your country
Ireland
Poison centre:
National Poisons Information Centre (public line)(01) 809 2166
Emergency: 112 · 999
Germany
Poison centre:
Emergency: 112
Mushroom advice: DGfM: find a mushroom expert. Certified mushroom experts of the German Mycological Society (DGfM).
Collecting rules: Mushrooms that are not specially protected may be collected in small quantities for personal use unless a protected area or ban applies. Certain specially protected edible species (e.g. cep, chanterelle, birch bolete) may be collected in small quantities for personal use.
Austria
Poison centre:
Vergiftungsinformationszentrale (VIZ)01 406 43 43
Emergency: 112 · 144
Mushroom advice: Austrian Mycological Society (ÖMG): mushroom advice. Mushroom advice by the Austrian Mycological Society or regional services such as municipal market offices.
Collecting rules: At most 2 kg of mushrooms per person per day unless the forest owner has prohibited collecting; organised collecting events are prohibited. Additional state rules apply (collecting hours, closed seasons), e.g. Carinthia, Tyrol, Vorarlberg, Salzburg.
Conservation and collecting rules
Not specially protected.
Salzburg: Collecting poisonous mushrooms is banned, except single specimens for identification.
Poisoning
ToxinMuscarine.
SyndromeMuscarine syndrome.
SymptomsSalivation, sweating, nausea, stomach cramps.
Onset15 to 30 minutes to a few hours.
What to do now: This is an emergency, even if there are no symptoms yet. Go to a hospital immediately or call 999 / 112 and the poison centre (NHS 111, England). Do not wait to see whether symptoms appear, and do not be misled by an apparent improvement. Do not induce vomiting. Keep leftover mushrooms, cleaning scraps and vomit, and tell everyone who shared the meal.
Frequently asked questions
Why does it turn red-brown?
Typical of Inosperma erubescens; St. George's mushroom does not stain like this.
How does it differ from St. George's mushroom?
St. George's mushroom: mealy smell, white spore print, smooth cap.
What should I do if I suspect poisoning?
Call the emergency number and the poison centre.
Related species
- Sulphur tuft Hypholoma fasciculare
- Fly agaric Amanita muscaria
- Devil's bolete Rubroboletus satanas
- Yellow-stainer Agaricus xanthodermus
- The sickener Russula emetica
- Spotted tricholoma Tricholoma pardinum
Sources
Photo credits
- Photo: Archenzo · CC BY-SA 3.0 · Wikimedia Commons
- St. George's mushroom: Photo: User:Strobilomyces · CC BY-SA 4.0 · Wikimedia Commons
No substitute for having your finds checked in person. No guarantee of accuracy. Updated: 17.10.2026.