Danny’s DNA Discoveries – Coprinus 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.
One of the most interesting results to come out of DNA studies was way back in 1994 (yes, they were sequencing way back then) when they found out that there are two families that create mushrooms that turn to ink, only distantly related to each other. The "shaggy manes" were closely related to the cultivated Agaricus portobello and button mushrooms, and everything else was most closely related to Psathyrella (you have to admit, sometimes they look like little inky caps that just don't turn to ink). Since the first Coprinus (inky cap) named was the shaggy mane, it got to keep the name Coprinus. All the others changed their genus and their family, with Psathyrella getting a promotion to having a family named after it, the Psathyrellaceae, to hold all the others.
How could such odd behaviour evolve twice? A current theory is that when gills evolve to be too crowded together, the spores can't escape. Remember, spores of Basidiomycota are forcibly ejected from the gills, they don't just "fall off". If the gills are too close together the spore will be thrown against the neighbouring gill, which is no good. That puts pressure to "evolve or die" another spore dispersal mechanism, and dissolving into ink was a solution to getting the spores dispersed, albeit as a liquid. You can fill a fountain pen and write or draw with mushroom ink, and like squid ink, it may be edible. I don't know of any dangerously poisonous inky caps, only some that make you very sick if eaten near the same time you consume alcohol.
Did you know that there are more than a half dozen different species of shaggy mane in the PNW? Did you know that the PNW is one of the places in the world where shaggy manes have been most studied, and that almost every single one of the species I talk about below, besides the common, universal shaggy mane Coprinus comatus var comatus, have their type (and only) collection described from Washington? Fred Van de Bogart described a number of species from WA in 1976 as part of his UW PhD requirements, but he seems to have only found each of them once and we have no known photographs of any of them. Not only that, nobody has ever reported finding any of them since, anywhere, that I know of. They are only known from Fred's original collections, but we have sequenced many of them, and in many cases they are indeed real, distinct genetic species! Are they rare or have they always been overlooked because nobody knows about them? So please be on the lookout for anything except the common Coprinus comatus var comatus and get good collecting data and photos so we can properly document these mushrooms.
Secotioid shaggy manes that may slightly turn to ink are Montagnea and Podaxis, genetically distinct enough to keep their own genera.
Coprinus - click to expand
All inky caps have black or nearly black spores and might have free gills (though often initially attached, they secede, or break off the stem fairly easily). Coprinus, the ones covered on this page, can be told apart from the Psathyrella relatives by having truly free gills even from birth (like Agaricus) and gills that can turn an intermediate colour of pink as they mature before they turn dark (like Agaricus). They also have very scaly (shaggy) caps that are an unusual umbrella shape, often much taller than they are wide. There is a well developed ring on the stem, and a cottony thread running through their hollow stem attached at both ends. Microscopically, sterile cystidia are only present on the gill edges and nowhere else.
Coprinus comatus var comatus
This abundant European species is found worldwide. It is rather large (let's say the cap is 6-12 cm tall (before it liquifies) and the stem adds up to another 20 cm to the height. It is found in grass or disturbed urban areas. Species found on dung or in deserts, or much smaller (caps 3 cm tall) or much larger (caps 12-24 cm tall and stem up to 50 cm tall) are different species described below.
But what is it? There are 2 genetic species commonly found in Europe but we don't know which one is the real one. var. comatus #1 is found in BC so far. If it is not the real thing, it will need a new name. var. comatus #2 is not found yet in the PNW, but it is really genetically close to var. parvus, below (4 bp and 1 indel different).
Coprinus comatus var parvus
The type sequences of these WA varieties differ in only one location in ITS, so they may not be distinct varieties. var. parvus is said to be on the small end (cap 4-5 cm tall) with some microscopic differences. var. caprimammillatus has some spores with an eccentric germ pore. It should be investigated if there is overlap in these features (if the microscopic differences of var. parvus can be found on specimens with some eccentric germ pores). Rare, var. parvus is only known from one collection in WA in 1951. var. caprimammillatus seems to be the only species he collected more than once (besides the very common var. comatus). He found it a total of 15 times, including once in Montana. It is also the only species of his that somebody else has ever found. We have a sequence of it from Victoria.
Coprinus comatus var excentricus
We don't have a type sequence of this AZ variety which was found once in AZ in 1973 and once in WA, but it has much larger spores than the others (14-18u long) and most of the spores have quite eccentric germ pores. It sounds like it is a valid variety. Rare.
Coprinus comatus © Fred Rhoades
This species has very large spores (17-20u long) and can also grow quite large (cap 12-24 cm tall, stem an additional 35-50 cm tall)! It was found in a somewhat dry area. Surprisingly, it is quite genetically close to Coprinus asterophoroides, a smaller desert species with similarly large spores (it differs by 3 bp in ITS). It should be investigated if this is really 2 species or just 1. Rare, known only from Washington in 1966.
Also with very large spores, but a small species (cap only 3 cm high and stem <12 cm tall) from desert areas. There is said to be a star shaped universal veil patch on the cap when young. Genetically very similar to the much larger Coprinus colosseus. Rare, known only from Washington in 1974.
A similar small, desert species with large spores, but instead of a star shaped patch, the universal veil remnants leave one irregular shaped patch or several smaller patches. It also has a bulbous, volvate stem base. DNA shows it is indeed a very distinct species. Rare, known from Washington and Utah in 1957. Both of these desert species may look like Montagnea at first glance, the secotioid genus described below.
The rest of these species are fairly small, described as "miniature shaggy manes".
This small UK species was reported once by Fred in WA. It was found on horse and cow dung. We need local and UK DNA to compare to see if this is indeed what Fred found.
This rare small WA species is found on deer or rabbit dung in the wild. The stem apex turns black in age. We do not have DNA to confirm that it is a unique species from Coprinus roseistipitatus. They both have the same size spores (8-10u long), but this species has spores that appear translucent brown in KOH under a scope, as opposed dark purplish grey for Coprinus roseistipitatus/palmeranus.
This similar deer or rabbit dung species has a pink stem apex in age, but white stem base. No clamp connections. The type sequence exactly matches the type sequence of Coprinus palmeranus in ITS. Rare, known from WA in 1975.
The type sequence is the same as Coprinus roseistipitatus, but it was found in grass and disturbed areas. Rarely, you can find a few microscopic clamp connections in the stem only, so it seems plausible that it could be the same species, where they were just overlooked or not present in the type collection of the Coprinus roseistipitatus.
Coprinus alnivorus and Coprinus arachnoideus
The two species that Fred placed in section Coprinus (in the case of Coprinus alnivorus because it has a ring) that turned out to be Psathyrella relatives instead of Coprinus species, are these two. Closer inspection reveals that they do not have a stem thread like other Coprinus and they do have pleurocystidia on the gill faces, which true Coprinus do not. To his credit, he noticed they fit kind of halfway between section Coprinus and other sections, and his placement was tentative. The former is a small, pale species of Coprinopsis that was found on wood that just has a little more developed ring than the others. It is very rare, or at least always overlooked. The latter turns out to be a synonym of Coprinellus flocculosus, as the type sequence is at most 2 bp different than all the European sequences of that mushroom.
Montagnea and Podaxis - click to expand
Secotioid relatives of the inky caps are not genetically close enough to belong in Coprinus, which is somewhat unusual. They do deserve their own genera. Montagnea is a sister genus to Coprinus. Podaxis is closer to Agaricus and may have somewhat independently developed inkyness.
The "desert shaggy mane" looks like a shaggy mane growing in the desert, but has a contorted spore mass instead of gills under the cap. It is surprising that it is not a sister genus to Comatus. I'm not sure what the type area is (Europe? India? ???) and we don't have local sequences, so more study is needed to determine what species of Podaxis we have here, although it seems to resemble P. pistillaris. Rare desert species.
Podaxis 'pistillaris' © Harley Barnhart
At first deeply buried, an outer membrane ruptures to leave a sac-like volva at the base of the stem. The cap is not taller than it is wide, unlike the other species on this page, but splits into a series of spore bearing plates (not gills). I believe it is a European mushroom, but we have neither European nor local sequences to compare to see which species we have, although it seems to resemble M. arenaria. Rare desert species.
Montagnea 'arenaria' © Michael Beug
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