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Danny’s DNA Discoveries – Panaeolus of the PNW
by Danny Miller

Click here for my Pictorial Key to Panaeolus


Panaeolus have very dark spores (usually black), fragile fruitbodies, dry, usually hygrophanous caps with a cellular cap cuticle and usually attached gills that easily come free. You might notice that so far, I've also described Psathyrella. The difference is that Panaeolus are more likely to have mottled gill faces from irregularly maturing spores (although the viscid Deconica might mottle as well), more likely to be found in dung or grass, and have a stiffer stem that is less likely to be white. There is very often a characteristic dark band around the outside of the cap as the centre of the cap dries out first (usually the edges of a cap are thinner and dry out first). According to Smith, Panaeolus can be told apart from Psathyrella microscopically by "brown basidiole-like bodies embedded in the hymenium". The two most confusing species might be Panaeolus foenisecii in grass, easily mistaken for a Psathyrella, and Psathyrella hirta, on dung, easily mistaken for a Panaeolus (but it is hairy).

It has been difficult to figure out what family Panaeolus should be in. They can be difficult to tell apart from Psathyrella, so they were placed in that family, but genetics showed they are too distantly related. Nothing else seemed to be very closely related, so the proper solution, somewhat obvious in retrospect, was that they deserved their own small family, almost of their own, the Galeropsidaceae. Unfortunately naming convention rules are a bit different with families than with other ranks, so we not supposed to call the family Panaeolaceae.

abundant common uncommon rare - colour codes match my Pictorial Key and are my opinions and probably reflect my bias of living in W WA. Rare species may be locally common in certain places at certain times.

Splotchy gill faces and stiff, non-white stem of Panaeolus (plus it was found in grass) © Danny Miller

Panaeolus foenisecii EU - Unusual for the genus, the spores are warty and not black (they're dark brown). There is no veil. As is common in the genus, the rim of the cap is often darker. It's also one of the only species not found on dung, but in grass, which makes its ecology different. This EU species appears to be found worldwide with very similar genetics.

Panaeolus castaneifolius NY is described as very subtly different (somewhat fewer spores will have guttules, for instance), but one well studied collection (MO#90428) had the same genetics as all the other Panaeolus foenisecii, and the differences really seem trivial to me, so I do not believe it is necessarily a distinct species.

Some have placed this species in a genus of its own, Panaeolina. Genetics show this species is nested inside of Panaeolus, not outside or beside it, so it doesn't need its own genus. This is the same situation as Leucocoprinus inside of Leucoagaricus, so I'm not going to say that there isn't some value in considering it its own genus. But although every other Panaeolus seems to have black spores, there are others in different clades with warty spores, so it's not that unique.

unsequenced Panaeolus foenisecii © Steve Trudell


Panaeolus 'olivaceus PNW01'  - P. olivaceus is a grass species with the usual black spores (described as slightly warty) described from the Faroe Islands between Denmark and Iceland. We don't have reliable sequences of it. P. 'olivaceus PNW01' resembles it microscopically and has been found in CA, ID, and WA, usually in grass, so it could represent this species.

Panaeolus 'olivaceus PNW02' - dark olivaceous black cap, radially rugose, convex-umbonate to broadly umbonate. Found once on the UBC campus in landscaping soil/mulch, which is not the right habitat, but it sequences very close to an Iranian sequence that was identified as P. olivaceus (only different a bit in ITS1). It was probably not correctly identified, but I don't know what else it could be.

Panaeolus 'olivaceus PNW01' © MO user Byrain,     P. 'olivaceus PNW02' from KY © Peter Ninneman (2 images)


Panaeolus PNW03 - this is a sand species, much like Psathyrella ammophila. We didn't think we had a sand Panaeolus, but here it is. According to Noah Siegel, unlike the Psathyrella, this species won't have a veil, is more likely to have grooves on the stipe, be a little stockier, and of course get mottled gills in age than the similar Psathyrellas.

Panaeolus PNW03 © Sadie Hickey, and Don Moore & Pam Buesing


Panaeolus papilionaceus EU (=P. campanulatus, =P. sphinctrus) - Genetics suggests that the EU species Panaeolus campanulatus and Panaeolus sphinctrus may be the same as the older EU species Panaeolus papilionaceus, as some have already suggested based on their similarities. Most ITS sequences of collections identified as any of the three names are basically identical. Found in dung with a bell shaped cap that is lead coloured. Up to 5cm. Veil material is often left hanging off the cap margin. The cap, like all caps of mushrooms with cellular cap cuticles, tends to wrinkle even though a separate variety was erected for wrinkled cap collections (keep reading).

Panaeolus papilionaceus var. retiruga EU - Interestingly, this variety, described with a wrinkled cap, does appear to have distinct ITS DNA. It was sequenced a couple times from WA. Unfortunately, there does not seem to be a pattern as to which variety is more likely to wrinkle (see photos). I do not know how to actually tell them apart.

Panaeolus papilionaceus var. papilionaceus (wrinkled cap) © Yi-Min Wang,     Panaeolus papilionaceus var. retiruga © Daniel Winkler


Panaeolus semiovatus EU (=P. phalenarum, =P. solidipes, =P. antillarum) - This species may have a ring, causing some to place it in its own genus, Anellaria. But not only does it not deserve its own genus, collections that are otherwise similar except without a ring do not have different ITS DNA, so the other names used for collections without a ring are now thought to be synonyms. If it doesn't have a ring, you might see veil material hanging off the cap like Panaeolus papilionaceus, but you can still recognize it by how stocky it is (stem up to a full 1 cm thick). We have DNA of this EU species confirmed from BC.

unsequenced Panaeolus semiovatus © Kit Scates Barnhart


Panaeolus alcis EU - Formerly called Panaeolus alcidis, this tiny Swedish species (<1 cm) without a veil has very similar ITS DNA to Panaeolus papilionaceus, if a well documented sequence from Sweden is to be believed, and it probably should be. Since this is one of the occasions where two clearly distinct species share very similar ITS DNA, it is possible that Panaeolus campanulatus and sphinctrus are distinct as well. Reported once from BC, but not confirmed by sequencing yet.

probable Panaeolus alcis © Paul Kroeger


Panaeolus subbalteatus UK - This species complex is one that often has a quite distinct dark band around the edge of the cap, in fact it's named after that feature. It grows on dung instead of grass and is somewhat larger than Panaeolus foenisecii (which doesn't have pure black spores). It has no veil and the cap flattens in age. BC and OR sequences match a bunch of EU type area sequences.

Panaeolus 'subbalteatus PNW04' - some sequences differ by a half dozen bp in one small part of ITS1 and again in one small part of ITS2. The differences are localized and not random like they should be. I don't know how to explain it, but we've seen similar sequences four times now, so it can't be a sequence error. Perhaps a whole chunk got deleted and a new chunk got inserted. At any rate, it is usually identified as Panaeolus cinctulus EU, which most people think is a synonym of P. subbalteatus, but that should be investigated. We have sequences of this from the EU (the type area of P. cinctulus), ENA and WNA.

A few other unique sequences in this group have been found. One BC sequence is 6bp different in ITS1 from P. subbalteatus. Another BC sequence seems to be a bad sequence as its 5.8s region has some differences, which usually doesn't happen. I'm on the lookout to find those sequences again.

Panaeolus acuminatus EU - This very similar more slender species might best be differentiated microscopically. It may or may not grow on dung, and might only be recognized if not on dung (for instance, in grass, as shown in the photo). This EU species was sequenced twice from WA, once from grass and once from dung. Most European sequences of Panaeolus acuminatus and Panaeolus rickenii EU match each other, so that could be a newer synonym.

Panaeolus fimicola EU - another similar smallish species that may or may not be on dung, a lot like P. acuminatus. Some sequences of this clade near the P. subbalteatus complex, but others don't. Panaeolus ater EU, with an almost black cap, may be the same thing as P. fimicola (it was originally a black capped variety of P. fimicola). We don't really have reliable sequences of this EU species, and we don't have any local DNA at all, but the single report from the PNW makes me wonder if it's really here. This group needs study.

Panaeolus subbalteatus © James Conway,     P. 'subbalteatus PNW04' © Yi-Min Wang,     P. acuminatus © Richard Morrison


Panaeolus cyanescens Asia - This species stains blue in age or where handled, due to the presence of Psilocybin. It is a Sri Lanka species reported all over the world and rarely in the PNW. DNA differs in India by 5 bp or so between some sequences, so it may be a variable species or there could possibly be more than one. We don't have any local DNA to compare yet.

unsequenced Panaeolus cyanescens © Michael Beug


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