Green-Staining Inocybe vs Liberty Cap
Inocybe aeruginascens compared with Psilocybe semilanceata — how to tell them apart in the field.
This is a dangerous confusion.
At least one of these species is toxic. Never eat a wild mushroom based on a photo comparison alone — verify with local experts.
Green-Staining Inocybe
Inocybe aeruginascens
ToxicPsychoactive
Liberty Cap
Psilocybe semilanceata
ToxicPsychoactive
How to Tell Them Apart
Also psilocybin-containing but very different habitat (grasslands, not under trees). Has a pointed nipple-like cap, gelatinous pellicle, and purple-brown spore print (not cigar-brown).
Side-by-Side Identification
| Trait | Green-Staining Inocybe | Liberty Cap |
|---|---|---|
| Cap | 2-5 cm across. Conical to campanulate, expanding to convex with a prominent umbo. Pale ochraceous to straw-brown, with distinctive radiating silky fibers typical of Inocybe. Surface dry, fibrillose. Margin often slightly splitting with age. | 0.5–2.5 cm across. Distinctly conical to bell-shaped with a pointed nipple (umbo) at the top that persists even when the cap opens. Cream to light brown when dry, darker olive-brown when wet. The surface has a translucent, slightly sticky quality when moist — you can see the gills through the cap if you hold it up to light. Develops a wavy margin with age. |
| Gills | Adnate to narrowly attached, crowded. Pale at first, becoming brownish with cigar-brown spore maturity. Edges may appear finely fringed (cystidia). | Narrowly attached to the stem (adnate). Start pale grey, mature to dark purple-brown as spores develop. Edges remain lighter — a white or pale fringe along the gill edge is a good diagnostic feature. |
| Stem | 3-7 cm tall, 3-6 mm thick. Whitish to pale brownish, fibrous-silky. Equal or slightly bulbous at the base. No ring. Bruises blue-green when damaged. | 4–10 cm tall but only 1–3 mm thick — extremely slender and wiry. Pale cream to yellowish, often with a slight blue-green tinge at the base when handled. Tough and flexible — you can bend it without it snapping. No ring. |
| Spore print | Cigar-brown to tobacco-brown (typical Inocybe — NOT purple-brown like Psilocybe). | Dark purple-brown to blackish. Essential for confirming ID — many small brown mushrooms look similar but have different spore colors. |
| Bruising | Blue-green bruising on stem and flesh when cut or damaged. This is distinctive for an Inocybe and indicates psilocybin content. Not always immediately obvious — may take several minutes to develop. | — |
| Odor | Mild, slightly spermatic — the characteristic Inocybe odor, though less pronounced than in many species of the genus. | Slightly musty, like damp hay. Nothing distinctive. |
| Habitat | Parks, gardens, roadsides, and managed urban landscapes, particularly under linden trees (Tilia), poplars (Populus), and willows (Salix). Prefers amended soils with wood chip mulch, composted bark, and nutrient-rich disturbed ground. Mycorrhizal with deciduous trees. | Unimproved grasslands — sheep and cattle pastures that haven't been treated with artificial fertilizers. Grows in the grass, not on dung. Loves acidic, boggy soil. Often found on hillsides, moorlands, and old meadows. Doesn't grow in gardens, forests, or plowed fields. |
| Season | May through October. Peaks in June and September in Central Europe. Can appear earlier in warm springs. | September through November in the Northern Hemisphere. Triggered by the first cold rains after summer — usually when night temperatures drop below 10°C. Peak season is mid-September to mid-October in the UK and Northern Europe. |
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.