St. George's Mushroom vs Deadly Fibrecap
Calocybe gambosa compared with Inocybe erubescens — how to tell them apart in the field.
This is a dangerous confusion.
At least one of these species is potentially deadly. Never eat a wild mushroom based on a photo comparison alone — verify with local experts.
How to Tell Them Apart
TOXIC. Fruits at a similar time in spring and can grow in similar habitats. Key differences: Inocybe erubescens has a fibrous, radially cracked cap (not smooth), gills that start white but turn olive-brown, a spermatic rather than mealy smell, and flesh that stains reddish. Contains muscarine.
Side-by-Side Identification
| Trait | St. George's Mushroom | Deadly Fibrecap |
|---|---|---|
| Cap | 5-15 cm across. Thick, fleshy, convex becoming wavy and irregular with age. White to cream, sometimes with a slight buff or yellowish tint. Surface smooth, dry, sometimes cracking at the margin in dry weather. | 3–9 cm across. Conical to bell-shaped when young, expanding to broadly umbonate with age. Ivory-white to straw-yellow when fresh, developing reddish-pink stains where handled or damaged. Surface is smooth to finely fibrillose (silky radial fibers). Margin may crack in dry weather. |
| Gills | Crowded, narrow, sinuate (notched where they meet the stem). White to cream. Do not change color significantly with age. | Crowded, initially pale whitish-cream, maturing to olive-brown as spores develop. Stain reddish-pink when bruised — this is the key diagnostic feature. Adnexed to almost free. |
| Stem | 3-7 cm tall, 2-4 cm thick. Stout, solid, white to cream. Smooth, fibrous, sometimes slightly swollen at the base. No ring, no volva. | 4–10 cm tall, 1–2 cm thick. White to pale cream, solid, often slightly bulbous at the base. Stains reddish when bruised or cut, particularly near the base. No ring. |
| Spore print | White. | Dull brown to snuff-brown. |
| Odor | Very strong, mealy, floury, like wet bread dough or fresh pasta. This smell is one of the most reliable identification features. | Faintly fruity or spermatic — typical Inocybe smell, though milder than some relatives. |
| Habitat | Grasslands, chalk downs, hedgerows, woodland edges, road verges, old orchards, and parklands. Prefers calcareous (chalky, limestone) soils. Often forms fairy rings or arcs. Can appear in the same locations year after year. Saprotrophic, feeding on dead organic matter in the soil. | Calcareous (lime-rich) soils under broadleaf trees, especially beech, oak, and lime (linden). Common in parks, gardens, roadsides, and woodland edges — basically wherever people walk. Ectomycorrhizal. |
| Season | Spring, typically April through June. Traditionally associated with St. George's Day (April 23rd) in the UK. Peak season is late April to mid-May in most of its European range. One of the earliest edible mushrooms to fruit each year. | Late spring through early summer — May to July in most of Europe. Occasionally into August in cooler regions. Overlaps dangerously with St. George's Mushroom season. |
Found one of these in the wild? Don't rely on memory — identify it from a photo with Orangutany and check it against both species before you touch it.