Boletales - gastroid

© Matt Trappe

Danny’s DNA Discoveries – gastroid Boletales of the PNW
by Danny Miller

Click here for my Pictorial Key to all gastroid fungi

Introduction

This page does not include gastroids and false truffles found in the gilled bolete families, those are found on that page. It also does not include gastroids and false truffles found in the Boletaceae or Suillaceae, those are found on that page.

Astreaus - earth stars that are hygroscopic (open, then maybe close in dry weather and re-open again in wet weather) and sometime have a checkered pattern on the inside of the rays. Most earth stars are in the Geastrales.

Scleroderma - the earth balls, with thick rinds and gleba that turns to dark purple-black powder.

Pisolithus - a closely related earth ball that has hundreds of seed like structures inside a vinaceous-brownish-black sticky substance

Rhizopogon - the classic underground false truffle, with spongy interior that turns olive green.

Sclerogaster - a rare, somewhat nondescript false truffle, this will be dealt with at a later date.

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.

Click here to download the FASTA data of all my DNA sequences

Summary of Interesting Results
Here are some of the newest, most interesting results of the study:

TBD

Astraus - click to expand
Species mentioned: Astraeus pteridis, hygrometricus, smithii

Astraeus pteridis OR - easily identified by the checkered pattern on the inside of the rays. We have an OR sequence that likely represents this and a bunch of sequences from Europe where they have it too, but no verified photographed sequenced collection.
Astraeus hygrometricus EU? Astraeus smithii MI? - not as easily identified because it lacks the distinct checkered pattern, so it is easily confused with various Geastrum species. However, Geastrum with either not be hygroscopic, have a beak around the apical pore, or have smaller spores than this. We're not even sure which species we have in the PNW. It has long assumed to be A. hygrometricus, but recently that was discovered to be a species complex and it was split into several different species. The only one of those found in North America so far is A. smithii, but they only checked the east coast. We need west coast sequences to find out what our species is. These are not the only two possibilities. Sometimes west coast species match east coast species (if so, we have A. smithii), sometimes they match European species and not the east coast species (if so, there are about 4 possibilities), and sometimes they turn out to be unique (if so, ours needs its own name). I don't know anybody who has any idea yet.
Astraeus PNW01 - found once partially opened (assuming it does open), matching a couple of NC sequences but likely unnamed.

unsequenced Astraeus pteridis © Kit Scates Barnhart, unsequenced A. hygrometricus group member © Michael Beug, A. PNW01 © Yi-Min Wang (2 images)

Scleroderma and Pisolithus - click to expand
Although the spore mass is white when immature, you'll hardly ever find one that young. Almost immediately they will start turning purplish-black inside, and at that point, at least, they are poisonous.
Species mentioned: Scleroderma albidum, areolatum, bovista, cepa, citrinum, floridanum, hypogaeum, laeve, meridionale, polyrhizum, verrucosum.

Pisolithus PNW01 - the "dead man's foot", an earthball easily separated from Scleroderma, its sister genus, by its larger size (up to 20cm across and 30cm high) an irregular sterile base, and most notably, hundreds of seed like structures inside a vinaceous-brownish-black sticky substance. It was long thought that our species was P. tinctorius or P. arhizus, but DNA shows that ours is distinct from both of them and probably needs a new name.

Pisolithus PNW01 © Jonathan Frank

Scleroderma cepa PNW01 - has a smoothish outer surface that might crack like mud in age (as shown in the photo) and then start to resemble the scaly species. The rind is fairly thick, usually >1mm. The spore size is inconsistently reported, but as it turns out our species has a sequence that does not match EU type area sequences of S. cepa, we'll probably have to describe our species with a new name and figure out exactly how the spores measure.
Scleroderma cf laeve ENA? - similar smoothish exterior and thick rind, but the round spiny spores measure 9-14u across. We don't have a reliable sequence of this species that seems to be from ENA, nor do we have local sequences to compare. We need more data.
Scleroderma 'albidum PNW03' - similar smoothish exterior and thick rind, but the round spiny spores measure 11-16u across. Our sequences don't match EU type area sequences, so I don't think we have the real species here, but ours probably needs a new name.
Scleroderma bovista EU - similar smoothish exterior and thick rind, but the round spiny spores have a reticulum joining the spines together and measure 11-17u across. We have a BC sequence that matches hundreds of EU type area sequences.
Scleroderma hypogaeum OR - similar smoothish exterior and thick rind, and like S. bovista, the round spiny spores also have a reticulum joining the spines together but measure 14-25u across. No DNA yet, we need local collections.

unsequenced Scleroderma cepa © A and O Ceska
Scleroderma PNW02 - the exterior is cracked like mud (areolate) from early on and the rind is somewhat thick (about 1mm thick). It's possible this species has been going by the names Scleroderma areolatum EU, but PNW02 is not nearly as close to S. areolatum as PNW04, described below.
Scleroderma areolatum EU - one WA sequence matches hundreds of EU sequences.
Scleroderma 'areolatum PNW04'- similar to S. areolatum and PNW02 and also cracking like mud from early on with a fairly thick rind ~1mm thick, but our one WA sequence is 9 bp different than the hundreds of EU type area sequences.
Scleroderma cf verrucosum EU - the exterior is covered in small scales that are blunt like the cracked patches of S. areolatum, but supposedly stick up somewhat. The rind is one of the thinnest in the genus, <1mm thick. We have many sequences of this from the EU, but no matching DNA has been found yet in the PNW. We need collections.
Scleroderma cf citrinum EU - the largest species (up to 10cm across) with one of the thickest rinds at >2mm thick, (except for the species that open up into a star shape) and the pointest scales that resemble rosettes. We have hundreds of EU type area sequences, but no local DNA. This should be low hanging fruit as it is quite common.

Scleroderma PNW02 © NAMA and the Field Museum of Natural History (2 images)

Scleroderma areolatum © Michelle Keller-Pearson (2 images),     S. 'areolatum PNW04' © Shannon Adams (2 images)

unsequenced Scleroderma verrucosum © Steve Trudell,     unsequenced S. citrinum © Michael Beug

Scleroderma cf floridanum FL - with small overlapping scales and a very thick rind (up to 5mm thick) this one opens up more completely into a star shape at maturity than most other species, but there's no puffball inside like in Geastrum and Astraeus, just the purple gooey/powdery mass. When young and unopened it's not easily differentiated from some of the above species. No DNA from anywhere yet.
Scleroderma cf polyrhizum EU - a smoothish exterior species with a similarly very thick rind that also opens up distinctly into a star shape. When young and unopened it's not easily differentiated from some of the above species. We have one EU sequence that may or may not be this, so we need both reliable type area sequences and local collections to compare, because we have none yet.
Scleroderma cf meridionale EU - with quite the rhizomorphic stem mass under the earthball and fairly thick peridium ~2mm thick, this species is distinctive. We have a few EU sequences that probably represent this, but no local DNA to compare yet.

unsequenced Scleroderma polyrhizum © Michael Beug,     unsequenced Scleroderma meridionale © Kit Scates Barnhart

Rhizopogon and Sclerogaster - click to expand
Rhizopogon - There are over 125 very similar looking Rhizopogon species reported from the PNW... SO FAR. Dealing with this genus is beyond the scope of this site.
Sclerogaster pacificus OR - features include a nearly spherical, dirty white fruitbody with a peridium that tends to disappear, a spore mass that is firm and finally friable, colored ochraceous buff, the cavities polyhedral and filled with spores, a sterile base present but columella not seen, and microscopic characters including round spores 7-8 um in diameter with very large verrucae, 9-10 per great circle. No DNA yet, so I can't guarantee we have the genus correct.

Rhizopogon sp. - the inside of this buried false truffle is a spongy mass that turns olive green to olive brown in age.

unsequenced Rhizopogon vinicolor © Matt Trappe

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