Panaeolus semiovatus: Potency, Trip Effects, Dosage & Growing

The Egghead Mottlegill[i] is in the same genus as several well-known psychoactive mushrooms and looks quite a bit like them, but not all pans are active—and this one might well not be. Officially, its status hasn’t been confirmed either way, which suggests it hasn’t produced a memorable experience for those who tried it, but might still have at least some psychoactivity, at least for some people, some of the time.

If you’re looking to trip, in other words, don’t eat this mushroom, but if you want to avoid tripping, don’t eat this mushroom! Plus, there are some reports of it causing minor gastric upset.

But mushrooms are fun to know about even if you can’t eat them, and learning to recognize this mildly toxic pan could save you some heartache if you’re looking for one of its magic cousins. It grows across most of Europe and North America, so that’s plenty of opportunity for a would-be psychonaut to end up disappointed and vaguely ill.

Identification & Description

Cap: Medium-sized, often egg-shaped when young, then opening widely or becoming convex with age. Slimy, sometimes wrinkled, but with no hairs or scales. Whitish to slightly tan. The interior flesh is white and soft.
Gills: Usually attached, especially when young. Initially very pale, then darkening in patches, before becoming all black. There may be hanging veil fragments around the rim.
Stem: Medium to long, but thin. Whitish, sometimes powdery. Young specimens usually have a thin, delicate ring, but this often breaks off and washes away by maturity. When present, the ring may be black, if spores have collected on it.
Smell: Nothing distinctive for identification.
Taste:  Nothing distinctive for identification.
Spores: Smooth, elliptical.
Spore Print: Black or blackish.
Habitat: Feeds on horse dung. Fruits from  dung singly or in groups in any season but winter.
Range: Widespread across Europe and  western North America.

The mottled appearance of the gills before the spores mature completely is distinctive of this entire genus—hence the name, mottlegill. The really unusual feature of this species[ii] is the stem ring, which most mottlegills lack. However, the ring is quite flimsy, and is usually missing from older specimens. Note that this mushroom likes horse dung. It’s unlikely to be found on cattle dung or other substrates.


The egghead looks more or less like a great many other mushrooms, including most other mottlegills, some psilocybes, and various other small, gray-brown, nondescript mushrooms, some of which are seriously poisonous, while others are safe to eat or psychoactive. It’s not that they all look exactly alike, it’s that the differences are subtle. The general “look” of these mushrooms isn’t a good indicator of identity. You actually have to look up and then check for all the details.


The egg-head mottlegill is not reliably psychoactive. Some people treat it as a culinary species, but as it’s not reliably safe, either, it may be better to let this one be.


The egg-head can cause mild gastrointestinal upset. Plus, while it’s not reliably psychoactive, it’s not reliably not psychoactive, either, and psilocybin does count as a poison for someone who wasn’t planning on tripping—and it could be dangerous if, for example, they were driving at the time.


[i]      (n.d.). Panaeolus semiovatus (Sowerby) S. Lundell—Egghead Mottlegill. First Nature

[ii]     Kuo, M. (2007). Panaeolus semiovatus. MushroomExpert

Leave a Comment