Danny’s DNA Discoveries – Panaeolus of the PNW
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.
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, 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.
Splotchy gill faces and stiff, non-white stem of Panaeolus (plus it was found in grass) © Danny Miller
Panaeolus foenisecii - Unusual for the genus, the spores are warty and not black (they're dark brown) so some have placed it in a genus of its own, Panaeolina, but genetics show this species is nested inside of Panaeolus, not outside or beside it, so it doesn't need its own genus. Besides, although every other Panaeolus seems to have black spores, there are others in different clades with warty spores. It's also one of the only species not found on dung, but in grass, which makes its ecology different. There is no veil. As is common in the genus, the rim of the cap is often darker. This EU species appears to be found worldwide with very similar genetics.
Panaeolus castaneifolius 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.
Panaeolus foenisecii © Steve Trudell
Panaeolus cf olivaceus - This grass species with the usual black spores (described from the Faroe Islands between Denmark and Iceland) was rumoured but never officially reported from the PNW. Something resembling it microscopically has now been found and sequenced twice in CA and once in WA, usually in grass. It has slightly warty spores.
Panaeolus cf olivaceus © MO user Byrain
Panaeolus papilionaceus (campanulatus, 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.
Panaeolus papilionaceus var. retiruga - Interestingly, this variety, with a wrinkled cap, does appear to have distinct ITS DNA. Species with cellular cap cuticles wrinkle very easily and for many other species, it turns out the wrinkled cap is NOT representative of different genetics. But this time, it does appear to be, at least for some collections. Confirmed from WA. We should get more collections to see if the wrinkled cap reliably separates the two genetic varieties. If not, I don't know how to tell them apart.
probable Panaeolus papilionaceus var. papilionaceus © Steve Trudell
Panaeolus semiovatus (phalenarum, solidipes, 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.
probable Panaeolus semiovatus © Kit Scates Barnhart
Panaeolus alcis - 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 complex - This species 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. Some local sequences of this UK species don't match the others, so it is either a variable species or perhaps we have the real thing as well as a sister species or two. We'll need more collections to find out. Some authors called this a complex of closely related species even before DNA sequences were made. Panaeolus cinctulus is thought by some to be the same thing, so at least it is probably one of the species in this complex (one possible sequence of it is related).
Panaeolus cf acuminatus - 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. This EU species is rarely reported from here, and we have no local sequences yet. There is some confusion over what species this name should be used for, so we also need reliable EU sequences to compare with.
Panaeolus cf fimicola - another similar smallish species that may or may not be on dung, a lot like P. acuminatus. Panaeolus ater may be the same thing, but it has an almost black cap. 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.
probable Panaeolus subbalteatus complex member © Michael Beug
Panaeolus cf cyanescens - 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.
probable Panaeolus cyanescens © Michael Beug
Panaeolus sp. UBC F-32268 - Dark olivaceous black cap, radially rugose, convex-umbonate to broadly umbonate. Found on UBC campus in landscaping soil/mulch. It has a unique sequence. Let's hope it turns up again.
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