ArticlePDF Available

On Sistotremastrum and similar-looking taxa (Trechisporales, Basidiomycota)

April 2021
Mycological Progress 20:453 - 476

April 2021
20:453 - 476

DOI:10.1007/s11557-021-01682-z

License
CC BY 4.0

Authors:

Viacheslav Spirin

University of Helsinki

Sergey Volobuev

Russian Academy of Sciences

Ilya Viner

University of Helsinki

Otto Miettinen

University of Helsinki

Show all 10 authorsHide

The taxonomy of Sistotremastrum (Trechisporales, Basidiomycota) is revised based on morphology and DNA data. The genus is shown to be polyphyletic, and therefore it is split into two units – Sistotremastrum s. str. and Sertulicium, gen. nov. (typified with Corticium niveocremeum). Sistotremastrum s. str. is retained for eleven species of which eight are described as new while Sertulicium encompasses at least six species, including one new to science. Both of these genera are only distantly related to other representatives of the Trechisporales. Additionally, a new poroid neotropical species, Porpomyces abiens (Hydnodontaceae), is described as morphologically similar to some members of Sistotremastrum s. str.

Phylogenetic relationships of the Trechisporales inferred from nrLSU sequences using Bayesian analysis. A 50% majority rule consensus phylogram. Bayesian posterior probabilities, ML bootstrap,

…

continued)

…

Phylogenetic relationships of Sertulicium inferred from ITS sequences using Bayesian analysis. A 50% majority rule consensus phylogram. Bayesian posterior probabilities, ML bootstrap, and MP

…

Basidiocarps of a Porpomyces abiens (holotype), b Sertulicium granuliferum (Miettinen 23459), c Sistotremastrum aculeatum (holotype), d S. mendax (Spirin 11208), e S. suecicum (Miettinen 13310), and f S. suecicum (senescent basidiocarps) (Miettinen 14548)

…

Microscopic structures of S. lateclavigerum (holotype). a Hyphae and hymenial cells. b Basidiospores

…

Figures - uploaded by Viacheslav Spirin

Content may be subject to copyright.

Content uploaded by Viacheslav Spirin

Content may be subject to copyright.

ORIGINAL ARTICLE

On Sistotremastrum and similar-looking taxa

(Trechisporales, Basidiomycota)

Viacheslav Spirin

&Sergey Volobuev

&Ilya Viner

&Otto Miettinen

&Josef Vlasák

&Nathan Schoutteten

Viviana Motato-Vásquez

&Heikki Kotiranta

&Hernawati

7,8

&Karl-Henrik Larsson

9,10

Received: 20 October 2020 / Revised: 28 December 2020 / Accepted: 2 February 2021

#The Author(s) 2021

Abstract

The taxonomy of Sistotremastrum (Trechisporales,Basidiomycota) is revised based on morphology and DNA data. The genus is

shown to be polyphyletic, and therefore it is split into two units—Sistotremastrum s. str. and Sertulicium, gen. nov. (typified with

Corticium niveocremeum). Sistotremastrum s. str. is retained for eleven species of which eight are described as new while

Sertulicium encompasses at least six species, including one new to science. Both of these genera are only distantly related to

other representatives of the Trechisporales. Additionally, a new poroid neotropical species, Porpomyces abiens

(Hydnodontaceae), is described as morphologically similar to some members of Sistotremastrum s. str.

Keywords Corticioid fungi .Phylogeny .Taxonomy .New taxa

Introduction

Sistotremastrum J. Erikss. is a genus of corticioid fungi typi-

fied with S. suecicum Litsch. ex J. Erikss. (Eriksson 1958).

Initially introduced for two species, it has been gradually ex-

panded to encompass smooth, effused basidiomycetes with

clavate basidia producing four to six sterigmata and smooth,

thin-walled, inamyloid basidiospores (Boidin and Gilles

1994; Telleria et al. 2013a,2014). Recently, Gruhn et al.

(2018) described two new Sistotremastrum species with a

hydnoid hymenophore and constantly four-sterigmatic basidia

and thus changed the present concept of the genus. As a con-

sequence, the morphological delimitation of Sistotremastrum

from Brevicellicium K.H. Larsson & Hjortstam and, partly,

from Trechispora P. Karst. became obscure. Another yet

persisting problem is the separation of Sistotremastrum from

Paullicorticium J. Erikss., which has a similar set of micro-

scopic characters (Eriksson et al. 1984). Oberwinkler (1965)

moved Sistotremastrum niveocremeum (Höhn. & Litsch.) J.

Erikss., one of the original species, to Paullicorticium,

stressing similarities in basidial development. Larsson et al.

(2004) included Paullicorticium ansatum Liberta in

Section Editor: Yu-Cheng Dai

*Viacheslav Spirin

viacheslav.spirin@helsinki.fi

Finnish Museum of Natural History, University of Helsinki, PO Box

7, 00014 University of Helsinki, Helsinki, Finland

Komarov Botanical Institute RAS, 2 Prof. Popov str, St.

Petersburg 197376, Russia

Biology Centre, Academy of Sciences of the Czech Republic,

Branišovská 31, 37005 České Budějovice, CZ, Czech Republic

Research Group Mycology, Department of Biology, Ghent

University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium

Núcleo de Pesquisa em Micologia, Instituto de Botânica, Av. Miguel

Estéfano 3687, São Paulo, SP 04301-902, Brazil

Finnish Environment Institute, Latokartanonkaari 11,

00790 Helsinki, Finland

The Herbarium (ANDA), Universitas Andalas, Padang, Sumatera

Barat 25163, Indonesia

Fakultas Kehutanan (Faculty of Forestry), Universitas

Muhammadiyah Sumatera Barat, Padang, Sumatera Barat 25172,

Indonesia

Natural History Museum, University of Oslo, PO Box 1172,

Blindern, 0318 Oslo, Norway

Gothenburg Global Biodiversity Centre, Post Box 461,

40530 Gothenburg, Sweden

https://doi.org/10.1007/s11557-021-01682-z

Mycological Progress (2021) 20:453–476

phylogenetic analyses of Agaricomycetes but were unable to

place it in one of the clades currently recognized as orders. On

the other hand, all Sistotremastrum species, including the ge-

neric type, have been found to be members of the

Trechisporales (Larsson 2007; Telleria et al. 2013a,2014;

Gruhn et al. 2018). However, most Paullicorticium species

have not yet been studied by DNA methods—in particular,

P. jacksonii Liberta whose connectionto Sistotremastrum was

discussed in the older literature (Eriksson et al. 1978). In the

present paper, we revise the generic limits of Sistotremastrum

and similar-looking taxa, and investigate species diversity

based on collections from different regions of Eurasia, as well

as from North and South America.

Materials and methods

Morphological study

Type specimens and collections from herbaria H, O, LE, S, GB,

MA, W, GENT, TRTC, LY, CWU, ANDA, MAN, SP, MG,

SING, as well as from the private herbarium of the author JV

were studied. Herbarium acronyms are given according to Thiers

(2019). Microscopic methods follow Miettinen et al. (2018). All

measurements were made from microscopic slides mounted in

Cotton Blue (abbreviated as CB in descriptions below), using

phase contrast and oil immersion lens (Leitz Diaplan microscope,

× 1250 amplification). In total, 20–30 basidiospores, 20 basidia

and subhymenial/subicular hyphae, and at least 10 basidioles and

hyphidia were measured for each specimen studied. The follow-

ing abbreviations are used in morphological descriptions: L—

mean basidiospore length, W—mean basidiospore width, Q

′—length/width ratio, Q—mean length/width ratio, n—number

of measurements per specimens.

DNA extraction, amplification, and sequencing

DNA was extracted from herbarium specimens using the

EZNA Forensic DNA kit (Omega Bio-tek) and AxyPrep

Multisource Genomic DNA Miniprep kit (Axygen

Biosciences, CA, USA) according to the manufacturer’sin-

structions, except that 50 μl of the elution buffer was used in

the elution step of the last one. The ribosomal ITS1–5.8S–

ITS2 region was amplified and sequenced with the fungal

specific primers ITS1F and ITS4B (Gardes and Bruns

1993). Sequences of nrLSU-rDNA were generated using

primers LR0R, CTB6, LR5, and LR7 (Vilgalys and Hester

1990; Haynes et al. 1995). PCR products were visualized

using agarose gel electrophoresis and Gel Red staining, and

subsequently purified with the Fermentas Genomic DNA

Purification Kit (Thermo Fisher Scientific, MA, USA). The

resulting products were sequenced with an ABI model 3130

genetic analyzer (Applied Biosystems, CA, USA) and

BigDye v.3.1 and ABI3730XL analyzer (Applied

Biosystems) by Macrogen. The raw data were edited and as-

sembled in MEGA 6 (Tamura et al. 2013).

Phylogenetic analyses

For this study, we generated 60 nrITS and 36 nrLSU se-

quences. All other sequences used in the analyses were

downloaded from GenBank (Benson et al. 2018)orUNITE

(Nilsson et al. 2018)(Table1). All newly generated sequences

were deposited in the INSDC.

Extremely high diversity of ITS sequences in the studied taxa

precludes attempts to construct a reliable all-encompassing align-

ment for all Sistotremastrum spp. However, we could distinguish

five alignable groups: S. niveocremeum complex, S. suecicum

and its closest relatives, S.aculeocrepitans and its closest rela-

tives, S.fibrillosum complex, and S.rigidum–vigilans clade. We

found it reasonable to exclude S. fibrillosum,aswellasnewly

described S.rigidum and S.vigilans from ITS analysis since

molecular evidence provided by nrLSU analysis is sufficient

for the purpose of our study. Therefore, we generated four align-

ments for this study: (1) nrLSU-alignment for the Trechisporales,

(2) nrITS-alignment for S. niveocremeum, (3) nrITS-alignment

limited to S. suecicum and its closest relatives, and (2) nrITS-

alignment for S.aculeocrepitans and its closest relatives. The

alignments were calculated through MAFFT 7.429 online server

(https://mafft.cbrc.jp/alignment/server/) using the L-INS-I strate-

gy (Katoh et al. 2017) and then manually adjusted. The align-

ments are deposited in TreeBASE (S25768).

For the genus-level analysis, a nrLSU dataset (1) was as-

sembled with representatives of Trechisporales (65 se-

quences). The resulting tree was rooted with Onnia leporina

and Sphagnomphalia brevibasidiata (Hymenochaetales) and

Sphaerobolus stellatus (Geastrales, Phallomycetidae). This

choice was guided by the current JGI Basidiomycota tree

(https://mycocosm.jgi.doe.gov/mycocosm/species-tree/tree;_

FJDxL?organism=basidiomycota) where Trechisporales is

recovered close to Hymenochaetales and Phallomycetidae.

After removing unalignable, ambiguous alignment positions,

the alignment length was 742 bp with 184 variable site

patterns. The three ITS datasets were assembled similarly:

the S. niveocremeum species complex alignment (2) contained

60 sequences and had the length of 329 bp with 40 variable

site patterns after removing unalignable, ambiguous positions.

The S. suecicum species complex analysis (3) contained 22

sequences, with alignment length of 508 bp with 13 variable

site patterns after removing ambiguous positions. The S.

aculeocrepitans species complex analysis (4) contained 22

sequences with the alignment length of 470 bp with 37 vari-

able site patterns. All the ITS trees are midpoint-rooted.

We inferred phylogenetic trees with maximum likelihood

(ML), maximum parsimony (MP), and Bayesian inference

(BI) but show here only the latter since all trees show

454 Mycol Progress (2021) 20:453–476

Table 1 Sequences generated for the present study

Species Specimen/herbarium Geographic origin (ISO code) Host GenBank number

nrITS nrLSU

Brevicellicium exile Spirin 8370 (H) US-WA Tsuga heterophylla MT002322 MT002338

B. olivascens Spirin 4446 (H) RU-NIZ Quercus robur MT002327 -

B. viridulum Kotiranta 29271 (H) RU-SAK Alnus hirsuta MN983275 -

Luellia cystidiata Læssøe 13875 (GB) DK Picea abies MW371211 MW371211

Porpomyces abiens Vlasák 1808/16 (H) GF Hardwood MN987945 MN987945

P. abiens Vlasák 1808/39 (H) GF Hardwood MN987942 MN987942

Pteridomyces galzinii Bernicchia 8122 (GB) IT Polystichum aculeatum MN937559 MN937559

Sertulicium granuliferum Spirin 9296 (H) RU-NIZ Populus tremula MT002321 -

S. granuliferum LE 292194 RU-ORL Betula pendula MT002325 MT002333

S. granuliferum LE 314053 RU-ORL Q. robur MT002313 MT002340

S. granuliferum LE 314054 RU-ORL Q. robur MT002315 MT002342

S. granuliferum LE 314055 RU-ORL B. pendula MT002314 MT002341

S. granuliferum LE 314056 RU-ORL Q. robur MT002316 MT002343

S. granuliferum LE 314057 RU-ORL Q. robur MT002312 MT002339

S. granuliferum Kotiranta 26776 (H) RU-TY Larix sibirica MT002323 -

S. granuliferum CWU 4704 UA Salix alba MT002326 -

S. granuliferum Miettinen 14813.2 (H) US-MA Cut bole MT075854 -

S. granuliferum Miettinen 16083 (H) US-MA Hardwood MT002319 -

S. granuliferum Miettinen 17272 (H) US-MA Quercus sp. MT002330 -

S. granuliferum Larsson 12282 (GB) US-TN Decayed wood MN937560 MN937560

S. granuliferum Larsson 12297 (GB) US-TN Decayed wood MN937561 MN937561

S. jacksonii Svantesson 699 (O) NO Picea abies MN937562 MN937562

S. jacksonii Spirin 10425 (H) RU-LEN P. abies MN987943 MN987943

S. jacksonii Miettinen 17141 (H) US-NY Abies sp. MN987944 -

S. lateclavigerum Spirin 13457 SI P. abies MW049161 -

S. niveocremeum Van Autgaerden S-20 (GENT) BE Hardwood MN947227 MN930920

S. niveocremeum Miettinen 14925.3 (H) FI Sorbus aucuparia (?) MT075855 -

S. niveocremeum Söderholm 4050 (H) FI Salix sp. MT075856 MT002334

S. niveocremeum Larsson 13727 (GB) FR Hardwood MN937563 MN937563

S. niveocremeum Kotiranta 26267 (H) RU-KRA Alnus sibirica MT075858 MT002337

S. vernale Söderholm 3886 (H) FI P. abies MT002311 MT664174

Sertulicium sp. 1 Spirin 5158 (H) RU-KHA Corylus mandshurica MT075857 MT002344

Sistotremastrum aculeatum Miettinen 10380.1 (H) CN-YN Hardwood (?) MN991176 MW045423

S. aculeatum Miettinen 13799.1 (ANDA) ID-SB Hardwood MN988623 -

S. aculeatum Dunaev KUN 1105 (H) TH Hardwood MN991181 -

S. aculeicrepitans Larsson 16097 (URM) BR-PB Hardwood MN937564 MN937564

S. aculeicrepitans Larsson 16478 (MG) BR-PA Hardwood MN937565 -

S. confusum Larsson 16004 (URM) BR-PE Hardwood MN937567 MN937567

S. confusum Larsson 16023 (URM) BR-PE Hardwood MN937566 -

S. denticulatum Motato-Vásquez 894 (SP) BR-SP Fallen branch MN954694 MW045424

S. fibrillosum Larsson 16988 (MG) BR-PA Hardwood MN937568 MN937568

S. geminum Miettinen 14333 (MAN) ID-PB Intsia bijuga MN991177 MN991177

S. induratum Spirin 8598 (H) US-WA Abies grandis MT002324 MT664173

S. induratum Spirin 8804 (H) US-WA Picea sitchensis MT002318 -

S. mendax J. Nordén 9579 (O) NO P. abies MN937569 -

S. mendax Larsson 12022 (O) NO P. abies MN937570 MN937570

S. mendax Miettinen 20946 (H) RU-LEN P. abies MN991179 -

455Mycol Progress (2021) 20:453–476

congruity of the phylogenetic signal. The best nucleotide sub-

stitution model was chosen with TOPALi 2.5 (Milne et al.

2008) based on the Akaike information criterion (AIC), which

were GTR + G + I (nst = 6, rates = invgamma) for the nrLSU-

dataset, GTR+G (nst = 6, rates = gamma) for the

S. niveocremeum dataset, and F81 (nst = 1) for the

S. suecicum dataset. The suggested models were implemented

in the Bayesian phylogenetic analyses. We performed

Bayesian inference with MrBayes 3.2 (Ronquist et al. 2012).

In the analyses, three parallel runs with four chains each, temp

= 0.2, were run for 3 million generations. All chains con-

verged to <0.01 average standard deviation of split frequen-

cies. A burn-in of 25% was used in the final analyses.

Maximum likelihood (ML) analysis was performed in

RAxML 7.2.8 (Stamatakis 2006) implemented in Geneious

version 9.1.8 (http://www.geneious.com) (Kearse et al.

2012). Following models suggested by TOPALi 2.5, we pre-

ferred to use the GTR model with gamma correction (GTR

GAMMA) in ML analysis. Bootstrapping was performed

using the “Rapid bootstrapping”algorithm with the number

of bootstrap replicates set as 1000. Maximum parsimony

(MP) analysis was performed using SeaView version 4

(Gouy et al. 2010) with the ignoring all gap sites option. The

number of bootstrap replicates was set as 1000.

Results

The nrLSU dataset encompasses all known genera of the

Trechisporales as defined by Larsson et al. (2004)and

Larsson (2007), with addition of Pteridomyces and

Suillosporium. The overall topologies of the Trechisporales

were highly similar (Fig. 1). They split the order into three

strongly supported clades:

(A) the Sistotremastrum s. str. subclade (pp = 1, bs = 99%)

includes the generic type, S. suecicum, and two un-

named closely related species (introduced below as

S. induratum and S. mendax), all with six-sterigmatic

basidia, plus eight more distantly related species with

four-sterigmatic basidia (S. aculeocrepitans,

S. fibrillosum and six new species);

(B) the S. niveocremeum subclade (pp = 1, bs = 100%)

covers five species formerly considered as members of

Sistotremastrum (except P. jacksonii and one unnamed

taxon) but separated below into a new genus,

Sertulicium. Morphological arguments for this solution

are given in the taxonomic part of the present paper.

Sistotremastrum guttuliferum is a younger synonym of

Trechispora granulifera, and therefore designated as

Sertulicium granuliferum in the phylogenetic trees; and

genera currently recognized in the family (Larsson 2007;

Liu et al. 2019). Among them, two sequences belong to an

unnamed poroid fungus from French Guiana introduced

below as Porpomyces abiens. Anatomically, its

basidiocarps are confusingly similar to the four-sterigmatic

Sistotremastrum species (i.e., S. aculeocrepitans,

S. fibrillosum, and a number of new species described in

this study) and differ from them mainly by a truly poroid

hymenophore and smaller basidiospores. Sequences of

three Brevicellicium species (including the generic type,

B. exile) showing considerable morphological similarity to

the four-sterigmatic Sistotremastrum species are also re-

solved in the Hydnodontaceae, in accordance to earlier

Table 1 (continued)

Species Specimen/herbarium Geographic origin (ISO code) Host GenBank number

nrITS nrLSU

S. rigidum Motato-Vásquez 833 (SP) BR-SP Fallen log MN954693 MW045435

S. suecicum Spirin 8932 (H) CA-BC Pinus contorta MT002317 -

S. suecicum Kunttu 5959 (H) FI Pinus sylvestris MT075859 MT002335

S. suecicum LE 295792 RU-ARK P. sylvestris MT002332 -

S. suecicum Miettinen 14550.1 (H) SE P. sylvestris MT075860 MT002336

S. suecicum Larsson 11849 (GB) SE P. abies (?) MN937571 MN937571

S. suecicum Miettinen 14829 (H) US-MA Fallen branch MT075861 -

S. suecicum Miettinen 16061 (H) US-MA Tsuga canadensis MT002328 -

S. suecicum Miettinen 16618 (H) US-MA Tsuga sp./Pinus sp. MT002331 -

S. vigilans Fonneland 2011-78 (O) NO P. abies MN937572 MN937572

S. vigilans Spirin 10097 (H) RU-LEN P. abies MN991178 -

S. vigilans Spirin 8778 (H) US-WA T. heterophylla MN991182 MN991182

Suillosporium cystidiatum Spirin 3830 (H) RU-KHA Picea ajanensis MN937573 MN937573

456 Mycol Progress (2021) 20:453–476

studies (Larsson 2007;Telleriaetal.2013b). Morphological

traits differentiating Sistotremastrum s. str. from

Brevicellicium and Trechispora are discussed in the taxo-

nomic part of this paper. As for the family-level rearrange-

ment of Sistotremastrum and Sertulicium,weaddressthis

question to further studies with the use of additional genetic

markers.

Additionally, three ITS datasets were constructed for the

new genus Sertulicium and the Sistotremastrum suecicum and

S. aculeocrepitans complexes to clarify species limits with the

use of larger amount of ITS sequences. The ITS-based topol-

ogy of Sertulicium (Fig. 2) indicates a presence of up to ten

species in the genus of which we have named six.

Furthermore, ITS sequences of S. jacksonii and S. vernale

reveal some differences (up to 1.4%) between European and

extra-European material. This may indicate that both species,

as they are here delimited, actually contain more than one

taxon. However, more samples and genetic markers are need-

ed to solve this problem. The second ITS-based phylogeny is

restricted to the S. suecicum complex (Fig. 3). It shows the

presence of at least two more species (described below as

S. induratum and S. mendax) morphologically similar and

phylogenetically close to the generic type of Sistotemastrum.

The third ITS-based phylogram shows phylogenetic relation-

ships of S. aculeocrepitans and up to five closely related spe-

cies. Of them, three are described as new to science, all having

four-sterigmatic basidia (S. aculeatum,S. denticulatum,and

S. geminum)(Fig.4). Four remaining Sistotremastrum species

(S. confusum,S. fibrillosum,S. rigidum,andS. vigilans)dealt

with in the present paper are represented in the nrLSU phy-

logeny (Fig. 1).Their ITS sequences are available inGenBank

(Table 1). Sequenced specimens are marked by asterisk.

Fig. 1 Phylogenetic relationships of the Trechisporales inferred from

nrLSU sequences using Bayesian analysis. A 50% majority rule

consensus phylogram. Bayesian posterior probabilities, ML bootstrap,

and MP bootstrap values are shown on nodes; branch lengths reflect

estimated number of changes per site

457Mycol Progress (2021) 20:453–476

Taxonomy

Porpomyces Jülich, Persoonia 11: 425, 1982.

The genus was initially introduced as monotypic,

encompassing only the type, Porpomyces mucidus (Pers.)

Jülich (Jülich 1982). Larsson (2001) showed it is related to

Trechispora. Another species, P. submucidus F. Wu & C.L.

Zhao, was recently described from China (Wu et al. 2015).

Here, we introduce the third representative of the genus,

P. abiens from South America. From P. mucidus and

P. submucidus,P. abiens differs by distinctly thick-walled

and tightly arranged hyphae in subiculum and trama. This

hyphal structure is clearly different from the loosely arranged,

rather delicate, thin- or only slightly thick-walled hyphae of

Fig. 2 Phylogenetic relationships of Sertulicium inferred from ITS

sequences using Bayesian analysis. A 50% majority rule consensus

phylogram. Bayesian posterior probabilities, ML bootstrap, and MP

bootstrap values are shown on nodes; branch lengths reflect estimated

number of changes per site

458 Mycol Progress (2021) 20:453–476

Fig. 3 Phylogenetic relationships

of Sistotremastrum suecium and

closely related taxa inferred from

ITS sequences using Bayesian

analysis. A 50% majority rule

consensus phylogram. Bayesian

posterior probabilities, ML

bootstrap, and MP bootstrap

values are shown on nodes;

branch lengths reflect estimated

number of changes per site

Fig. 4 Phylogenetic relationships

of Sistotremastrum

aculeocrepitans and closely

related taxa inferred from ITS

sequences using Bayesian

analysis. A 50% majority rule

consensus phylogram. Bayesian

posterior probabilities, ML

bootstrap, and MP bootstrap

values are shown on nodes;

branch lengths reflect estimated

number of changes per site

459Mycol Progress (2021) 20:453–476

P. mucidus and P. submucidus. The two latter species have

thin-walled basidia and no sterile hymenial elements while

basidia are slightly thick-walled in a senescent hymenium of

P. abiens and hyphidia are present. Rather tough basidiocarps

consisting of predominantly thick-walled hyphae and short,

tardily thick-walled basidia of P. abiens are reminiscent of

hydnoid-semiporoid Sistotremastrum species, i.e.,

S. aculeatum,S. aculeocrepitans,andS. denticulatum.The

only reliable anatomical traits differentiating them from

P. abiens are their suburniform basidia and somewhat larger

basidiospores. Moreover, no truly poroid species are so far

known in Sistotremastrum s. str.

Porpomyces abiens Vlasák & Spirin, sp. nov.—Figs. 5and

MB 833939

Holotype. French Guiana. Remire-Montjoly: Lac du

Rorota, rotten angiosperm wood, 23.VIII.2018 Vlasák

1808/16* (H 7009714).

Etymology.Abiens (Lat., part. from abeo)—departing,

deviating.

Basidiocarps effused, first soft-floccose, then rather tough,

covering several cm, 0.2–1 mm thick. Hymenial surface pale

cream-colored to yellowish or pale ochraceous, poroid, pores

angular to sinuous, partly fusing together, strongly elongated

on sloping substrate, 6–9 per mm, with thin, entire dissepi-

ments. Margin white to pale cream-colored, fibrillose or com-

pact, in some portions with thin, white, pronounced hyphal

strands.

Hyphal structure monomitic; hyphae clamped.

Subicular hyphae slightly to distinctly thick-walled,

(2.2–)2.7–7.3 (–7.8) μm in diam. (n = 20/1), interwoven

or in subparallel bundles, often distinctly inflated (up to

10 μm); some hyphae encrusted by densely distributed

thorn-like crystals or subglobose resinous globules.

Tramal hyphae distinctly thick-walled, rather tightly ar-

ranged, interwoven to subparallel, occasionally anasto-

mosing, partly glued together, (2.2–)2.8–5.8 (–6.4) μm

in diam. (n = 40/2), sometimes inflated near septa; some

hyphae encrusted by densely distributed subglobose res-

inous globules. Subhymenial hyphae thin- to slightly

thick-walled, mostly short-celled and distinctly inflated,

(2.0–)2.2–5.2 (–5.4) μm in diam. (n = 40/2). Rhomboid

or prismatic crystals occasionally present among subicular

or tramal hyphae, up to 15 μm in widest dimension, sol-

itary or in large groups. Hyphidia rarely present, 10–12 ×

3.5–5μm. Basidia subglobose to barrel-shaped or shortly

clavate, 2–4-spored, (4.8–)4.9–7.9 (–8.0) × (3.4–)3.7–

4.8 (–5.0) μm (n = 30/2), senescent basidia slightly thick-

walled. Basidioles subglobose to globose, 4–5×4–4.5

μm. Basidiospores broadly cylindrical to ellipsoid, more

rarely somewhat tapering to the apex (lacrymoid), (2.3–)

2.5–3.2 (–3.3) × (1.6–)1.7–2.2 (–2.3) μm(n=60/2),L=

2.87–2.94, W = 1.98–2.00, Q = 1.46–1.47, contents ho-

mogeneous and CB (+).

Remarks. Porpomyces abiens has been detected in three

localities in French Guiana. It seems to be a saprotrophic spe-

cies occurring on wood remnants, various debris and soil.

Specimens examined. French Guiana. Remire-Montjoly:

Lac du Rorota, hardwood, 23.VIII.2018 Vlasák 1808/39*

(H, JV). Roura: Natural Reserve of Kaw, Patawa Lodge, on

soil between the roots of uprooted tree, 31.VIII.2018 Vlasak

1808/146 (JV), Amazon Lodge, rotten hardwood log,

4.IX.2019 Vlasák 1909/29* (JV).

Sertulicium Spirin, Volobuev & K.H. Larss., gen. nov.

MB 833941

Etymology.Sertulum (Lat., noun)—a small chaplet.

Basidiocarps effused, very thin to rather thin (usually up to

0.1 mm thick), pruinose or waxy. Hymenophore smooth.

Hyphal structure monomitic; all hyphae clamped, CB (+).

Cystidia mostly absent, hyphidia rarely present, simple.

Basidia clavate, with 4–6 sterigmata, normally not collapsing

at the apex. Basidiospores thin-walled (but the wall distinct),

narrowly ellipsoid to cylindrical, inamyloid, acyanophilous,

contents homogeneous and CB (+). On rotten wood of decid-

uous trees and conifers.

Generic type.Corticium niveocremeum Höhn. & Litsch.

Morphological differences between Sertulicium and

Sistotremastrum s. str. cannot be easily grasped due to

the extreme anatomical simplicity of their representa-

tives. Nevertheless, some distinguishing characters are

indicated here awaiting more in-depth analysis in the

future. First, all but one Sertulicium spp. are extremely

thin fungi consisting of a few subicular hyphae and the

overlying subhymenium. The subicular hyphae are

scattered; i.e., they do not produce hyphal strands so

characteristic for most Sistotremastrum s. str. species

studiedbyus.TheonlyexceptionisSertulicium

granuliferum, having the most elaborate fructifications

in the genus. Its basidiocarps start their development as

radially arranged hyphal bundles becoming quickly cov-

ered by randomly arranged hyphae and finally indiscern-

ible. In contrast, in Sistotremastrum s. str. subicular hy-

phal strands can be detected even in senescent

basidiocarps if hyphae are not totally collapsed.

Second, basidia in all Sertulicium spp. bear up to six

sterigmata while at least some Sistotremastrum s. str.

species are strictly four-sterigmatic. Moreover, apical

parts of basidia in the latter genus often collapse, and

hymenial cells of this kind dominate in well-developed

and in senescent basidiocarps. Such apically collapsing

basidia may occur in Sertulicium spp., too, but they are

as a rule rare. Finally, all Sertulicium spp. have a smooth

hymenial surface while about a half of the currently

460 Mycol Progress (2021) 20:453–476

known Sistotremastrum spp. have a hydnoid

hymenophore.

Sertulicium chilense (Telleria, M. Dueñas & M.P.

Martín) Spirin & Volobuev, comb. nov.

≡Sistotremastrum chilense Telleria, M. Dueñas & M.P.

Martín, Phytotaxa 158: 94, 2014 (as ‘chilensis’).

MB 833942

Sistotremastrum chilense was described from Patagonia

(Telleria et al. 2014) as a relative of S. guttuliferum (see under

Sertulicium granuliferum below). From the latter species, it

differs primarily in having long-celled subhymenial hyphae

(vs. short-celled and somewhat inflated in S. granuliferum).

DNA data confirm its placement in Sertulicium.

Sertulicium granuliferum (Hallenb.) Spirin & Volobuev,

comb. nov.—Figs. 5and 10

MB 833943

≡Trechispora granulifera Hallenb., Iranian J. Plant Path.

14: 77, 1978. Holotype. Iran. Gilan: Asalem, Parrotia persica,

16.VII.1976 Hallenberg 1885 (GB 23442, studied).

= Sistotremastrum guttuliferum Melo, M. Dueñas, Telleria

& M.P. Martín, Mycological Progress 12: 688, 2013.

Holotype. Portugal. Madeira: Santana, decayed wood,

19.X.2006 Telleria 16566* (MA F82105, studied).

Basidiocarps effused, initially reticulate, soft-pellicular,

then continuous, waxy, covering several cm, 0.05–0.1 mm

thick. Hymenial surface first cream-colored, later yellowish

to pale ochraceous, smooth or indistinctly tuberculate,

Fig. 5 Basidiocarps of a

Porpomyces abiens (holotype), b

Sertulicium granuliferum

(Miettinen 23459), c

Sistotremastrum aculeatum

(holotype), dS. mendax (Spirin

11208), eS. suecicum (Miettinen

13310), and fS. suecicum

(senescent basidiocarps)

(Miettinen 14548)

461Mycol Progress (2021) 20:453–476

occasionally cracking in senescent basidiocarps. Margin first

pruinose, later compact and rather sharply delimited. Small

white patches spread at the marginal areas of young speci-

mens, consisting of crystal agglomerations.

Hyphal structure monomitic; hyphae clamped, quickly col-

lapsing. Subicular hyphae subparallel (juvenile specimens) to

interwoven, thin- or slightly thick-walled, branched mostly at

right angles, (3.0–)3.1–6.5 (–6.9) μm in diam. (n = 100/5).

Subhymenial hyphae thin-walled, densely arranged, some

short-celled and slightly inflated, (2.2–)2.3–4.2 (–4.6) μmin

diam. (n = 100/5). Hyphidia occasionally present, embedded,

simple, 3–4μm in diam. Basidia clavate, 4–6-spored, gradually

tapering to the basal part, (11.3–) 13.6–30.2 (–32.7) × (4.3–)4.4–

6.6 (–6.7) μm (n = 100/5). Basidioles clavate to bladder-shaped,

(7.3–)9.1–13.8 (–14.6) × (4.7–)4.8–7.2 (–7.3) μm(n=30/2).

Basidiospores cylindrical, straight, rarely slightly curved, (4.8–)

4.9–7.3 (–8.0) × (2.3–)2.5–3.3 (–3.5) μm (n = 270/9), L = 5.40–

6.76, W = 2.78–3.07, Q = 1.81–2.41.

Remarks. This species was introduced as a member of

Trechispora due to some morphological similarity to the

smooth-spored members of that genus (i.e., Trechispora

cohaerens group) (Hallenberg 1978). Larsson (1992)found

clavate basidia with 4–5 sterigmata in the type collection

and thus pointed towards possible affinities with

Sistotremastrum. After rechecking the type, as well as mor-

phological and DNA studies of newly collected material, we

conclude that T. granulifera is an older name for the species

recently introduced as Sistotremastrum guttuliferum (Telleria

et al. 2013a). Consequently, a new combination is proposed.

Sertulicium granuliferum differs from the similar-looking

S. niveocremeum in having thicker and softer basidiocarps

with a well-developed subicular layer and smaller basidio-

spores (Table 2).

Sertulicium granuliferum is widely distributed in temperate

Eurasia. It seems to be not rare along the eastern coast of

Canada and the USA, and its distribution in North America

stretches to the central part of Mexico. All but one specimen

came from wood remnants of deciduous trees, mostly from

decayed wood but a few from still corticated, rather tough

branches or logs. One specimen from Ethiopia is morpholog-

ically indistinguishable from other collections studied by us

and therefore accepted here as S. granuliferum. Three other

collections from Africa (Kenya and Tanzania) are microscop-

ically identical to S. granuliferum but strikingly different mac-

roscopically due to a well-developed, distinctly fibrillose mar-

gin. They may represent yet another species in this genus and

thus treated as Sertulicium aff. granuliferum under Specimens

examined. ITS regions of two published Sistotremastrum ge-

nomes (Nagy et al. 2016;Sistotremastrum niveocremeum

LOAV00000000.1 and Sistotremastrum suecicum

SRA:SRR1800527.68548550.2) appear to be conspecific

and belong to Sertulicium granuliferum.

Specimens examined. Belgium. Oost-Vlaanderen:

Kluisbergen, Kluisbos, deciduous wood, 20.II.2017

Schoutteten 17-021, 17-022 (GENT), 7.III.2017 Schoutteten

17-108 (GENT). Canada. Québec: Outaouais, Gatineau Nat.

Park, angiosperm, 17.X.1967 Eriksson 9155 (GB), Acer sp.,

17.X.1967 Eriksson 9177 (GB). Ethiopia. Shoa Prov.:

Shashemene, dead hardwood twig, 18.VII.1990 Ryvarden

28557 (O). Germany. Nordrhein-Westphalen: Essen,

Werden, deciduous wood, 6.I.2020 Miettinen 23459 (H).

Italy. Lombardy: Varese, Valganna, San Gemolo, Fraxinus

excelsior,14.X.2019Spirin 13657 (H). Mexico. Vera Cruz:

Barranca de Pescado, angiosperm, 26.IX.1985 Ryvarden

23449 (O). Russia. Kemerovo Reg.: Novokuznetsk Dist.,

Kuzedeevo, Betula sp., 3.IX.2011 Kotiranta 28540 (H),

Salix caprea, 4.IX.2011 Kotiranta 28597 (H). Leningrad

Reg.: Boksitogorsk Dist., Chagoda, Alnus incana,9.V.2018

Spirin 11877 (H). Nizhny Novgorod Reg.: Bogorodsk Dist.,

Krastelikha, Tilia cordata, 14.IX.2010 Spirin 3503 (H),

Q. robur, 2.X.2015 Spirin 9898,9899,9910 (H),

17.VII.2016 Spirin 10310, 10313, 10315 (H), 5.V.2018

Spirin 11862 (H); Lukoyanov Dist., Panzelka, Padus avium,

17.VIII.2015 Spirin 9479 (H), 9.VIII.2016 Spirin 10577 (H),

Razino, Populus tremula, 15.VIII.2015 Spirin 9296* (H),

Q. robur,10.VIII.2016Spirin 10605 (H), T. cordata,

23.VII.2018 Spirin 12006 (H), Sanki, Acer platanoides,

20.VIII.2015 Spirin 9658 (H); Pavlovo Dist., Chudinovo,

P. tremula, 3.X.2015 Spirin 9977 (H), 15.VII.2016 Spirin

10281, 10284 (H), T. cordata, 15.VII.2016 Spirin 10263

(H). Oryol Reg.: Krasnozorensky Dist., Malinovo, Q. robur,

7.X.2012 Volobuev (LE 314056*); Novoderevenkovsky

Fig. 6 Microscopic structures of P. abiens (holotype). aSubicular

hyphae. bHymenial cells. cTramal hyphae. dBasidiospores

462 Mycol Progress (2021) 20:453–476

Table 2 Basidiospore dimensions of Porpomyces and Sistotremastrum s. lato species. Species name and basidiospore dimensions for a given taxon are

presented in bold

Species/specimen L′LW′WQ′Qn

Porpomyces abiens (2.3) 2.5–3.2 (3.3) 2.91 (1.6) 1.7–2.2 (2.3) 1.99 (1.2) 1.3–1.7 (1.8) 1.47 60

holotype (2.4) 2.5–3.2 (3.3) 2.94 (1.6) 1.7–2.2 2.00 (1.2) 1.3–1.7 (1.8) 1.47 30

Vlasák 1808/39 (2.3) 2.6–3.2 (3.3) 2.87 (1.7) 1.8–2.2 (2.3) 1.98 (1.3) 1.4–1.6 (1.7) 1.46 30

Sertulicium granuliferum (4.8) 4.9–7.3 (8.0) 5.75 (2.3) 2.5–3.3 (3.5) 2.90 (1.5) 1.6–2.4 (2.5) 2.02 270

Kotiranta 26776 5.1–6.7 (6.8) 5.70 (2.6) 2.7–3.2 (3.3) 2.88 (1.6) 1.8–2.2 (2.3) 1.98 30

Larsson 12282 (5.0) 5.1–6.0 (6.1) 5.46 (2.7) 2.8–3.2 (3.3) 3.02 (1.6) 1.7–2.0 (2.1) 1.81 30

LE 299057 (4.8) 4.9–6.0 (6.1) 5.40 (2.5) 2.6–3.2 2.83 (1.6) 1.7–2.1 (2.2) 1.91 30

Miettinen 16083 (6.0) 6.1–7.3 (8.0) 6.76 (2.7) 2.8–3.3 (3.5) 3.07 (1.8) 2.0–2.4 2.21 30

Spirin 3503 (5.1) 5.2–6.2 (6.3) 5.82 (2.6) 2.7–3.1 (3.2) 2.85 (1.8) 1.9–2.3 (2.4) 2.04 30

Spirin 9296 5.2–6.5 (7.0) 5.95 (2.6) 2.7–3.2 2.87 (1.6) 1.8–2.4 (2.5) 2.41 30

Spirin 9898 (4.9) 5.0–6.1 (6.2) 5.46 (2.6) 2.7–3.2 (3.3) 2.86 (1.6) 1.7–2.1 (2.2) 1.92 30

Spirin 9977 (4.8) 5.1–6.6 (7.2) 5.63 (2.6) 2.7–3.3 (3.5) 2.97 (1.5) 1.6–2.2 (2.3) 1.91 30

Telleria 16566 (4.9) 5.0–6.1 (6.2) 5.56 (2.3) 2.5–3.1 (3.3) 2.78 (1.7) 1.8–2.2 (2.3) 2.00 30

S. jacksonii (5.1) 5.2–8.2 (8.6) 6.60 (2.7) 2.8–4.1 (4.2) 3.29 (1.5) 1.6–2.6 (2.7) 2.02 170

holotype (6.1) 6.2–8.0 (8.2) 7.13 (2.7) 2.8–3.2 (3.3) 2.99 2.2–2.6 (2.7) 2.39 20

Bernicchia 5464 (5.3) 5.7–7.3 (7.8) 6.52 (3.2) 3.3–4.1 (4.2) 3.66 (1.5) 1.6–2.1 (2.2) 1.79 30

Laurila 3256b (5.2) 5.3–7.2 6.43 (2.7) 2.8–3.8 (4.0) 3.23 (1.8) 1.9–2.5 (2.6) 2.00 30

Miettinen 17141.2 (6.0) 6.1–8.2 (8.6) 6.96 3.0–3.4 (3.5) 3.21 (1.9) 2.0–2.5 2.17 30

Spirin 10425 (5.2) 5.6–7.4 (8.0) 6.49 (2.8) 2.9–3.8 (3.9) 3.30 (1.6) 1.7–2.3 (2.6) 1.97 30

Svantesson 699 (5.1) 5.2–6.8 (7.1) 6.08 (3.0) 3.1–3.9 (4.0) 3.36 (1.5) 1.6–1.9 (2.3) 1.81 30

S. lateclavigerum (4.3) 4.6–7.2 (7.3) 5.57 (2.1) 2.2–3.2 2.71 (1.7) 1.8–2.4 (2.5) 2.07 60

holotype (4.9) 5.0–7.2 (7.3) 5.82 (2.5) 2.6–3.2 2.84 (1.7) 1.8–2.3 (2.4) 2.05 30

Spirin 13457 (4.3) 4.6–6.2 (7.2) 5.32 (2.1) 2.2–3.0 (3.1) 2.57 (1.7) 1.8–2.4 (2.5) 2.09 30

S. niveocremeum (5.2) 5.5–8.6 (9.8) 6.86 (2.6) 2.7–4.2 (4.3) 3.25 (1.6) 1.7–2.4 (2.6) 2.12 120

holotype (5.2) 5.5–7.8 (9.8) 6.62 (2.6) 2.7–3.6 (4.3) 3.12 (1.7) 1.9–2.4 (2.5) 2.12 30

Kotiranta 26267 (5.7) 6.0–7.4 (7.6) 6.55 (2.7) 2.8–3.4 (3.5) 3.08 (1.9) 2.0–2.3 (2.5) 2.13 30

Miettinen 14925.3 (6.0) 6.1–8.6 (9.2) 7.46 (3.0) 3.1–3.6 (3.8) 3.33 (1.7) 1.8–2.4 (2.6) 2.24 30

Söderholm 4050 (6.0) 6.1–7.7 (7.8) 6.79 (3.0) 3.1–4.2 (4.3) 3.46 (1.6) 1.7–2.2 (2.3) 1.97 30

S. vernale (5.7) 5.8–8.2 (8.3) 6.96 (2.8) 2.9–3.8 (3.9) 3.30 (1.6) 1.8–2.5 (2.9) 2.12 60

holotype (5.7) 6.1–8.2 (8.3) 7.02 (2.8) 2.9–3.8 3.28 (1.6) 1.8–2.5 (2.9) 2.15 30

Spirin 14244 (5.7) 5.8–8.0 (8.1) 6.90 (2.9) 3.0–3.8 (3.9) 3.31 (1.6) 1.8–2.3 (2.4) 2.09 30

Sistotremastrum aculeatum (4.1) 4.2–6.2 (6.8) 5.03 (2.1) 2.2–3.1 (3.3) 2.58 (1.5) 1.6–2.4 (2.7) 1.97 120

holotype (4.1) 4.2–6.2 (6.8) 5.07 (2.2) 2.3–3.1 (3.3) 2.65 (1.5–)1.6–2.4 (2.7) 1.94 60

Dunaev KUN1105d 4.2–5.3 (5.4) 4.98 (2.1) 2.2–3.0 (3.1) 2.60 (1.6–)1.7–2.4 (2.5) 1.94 30

Miettinen 10380.1 (4.2) 4.3–6.1 (6.2) 5.05 (2.2) 2.3–2.8 (3.0) 2.50 1.8–2.2 (2.3) 2.03 30

S. aculeocrepitans (4.0) 4.1–5.6 (5.8) 4.77 (2.1) 2.2–2.8 (2.9) 2.33 1.8–2.5 (2.6) 2.06 60

Larsson 16097 (4.4) 4.5–5.6 (5.8) 5.10 (2.1) 2.2–2.8 (2.9) 2.35 (1.8) 1.9–2.5 (2.6) 2.19 30

Larsson 16478 (4.0) 4.1–5.0 (5.1) 4.44 (2.1) 2.2–2.6 (2.7) 2.30 1.8–2.1 (2.2) 1.93 30

S. confusum (5.3) 5.7–7.6 (7.9) 6.56 2.9–3.9 (4.0) 3.24 (1.7) 1.8–2.3 (2.6) 2.03 60

holotype (5.3) 5.7–7.3 (7.8) 6.54 2.9–3.4 (3.8) 3.16 (1.7) 1.8–2.3 (2.6) 2.07 30

Larsson 16004 (5.3) 5.7–7.6 (7.9) 6.57 3.0–3.9 (4.0) 3.32 (1.7) 1.8–2.3 (2.4) 1.99 30

S. denticulatum (3.9) 4.0–5.3 (5.4) 4.51 (2.0) 2.1–3.0 (3.1) 2.48 (1.5) 1.6–2.3 (2.4) 1.83 30

holotype (3.9) 4.0–5.3 (5.4) 4.51 (2.0) 2.1–3.0 (3.1) 2.48 (1.5) 1.6–2.3 (2.4) 1.83 30

S. fibrillosum (4.0) 4.2–5.2 (5.6) 4.72 (2.1) 2.2–2.9 (3.0) 2.53 (1.6–)1.7–2.1 (2.2) 1.88 20

Larsson 16988 (4.0) 4.2–5.2 (5.6) 4.72 (2.1) 2.2–2.9 (3.0) 2.53 (1.6–)1.7–2.1 (2.2) 1.88 20

S. geminum (3.8) 3.9–5.2 (5.5) 4.28 (1.9) 2.0–2.6 (2.9) 2.24 (1.7) 1.8–2.2 (2.3) 1.92 30

holotype (3.8) 3.9–5.2 (5.5) 4.28 (1.9) 2.0–2.6 (2.9) 2.24 (1.7) 1.8–2.2 (2.3) 1.92 30

S. induratum (4.0) 4.1–5.3 (5.8) 4.55 (2.5) 2.6–3.1 (3.2) 2.83 1.4–1.8 (1.9) 1.62 60

463Mycol Progress (2021) 20:453–476

Dist., Mokhovoe, Q. robur, 24.VII.2011 Volobuev (LE

314057*); Sverdlovsky Dist., Maryevka, Betula pendula,

1.IX.2012 Volobuev (LE 314055*); Uritsky Dist.,

Naryshkino, B. pendula, 6.X.2012 Volobuev (LE 292194*),

Q. robur, 25.VI.2011 Volobuev (LE 314054*), 6.X.2012

Volobuev (LE 314053*). Primorie Reg.: Ternei Dist., Maisa,

hardwood stump, 9.IX.1990 Larsson 7182 (GB), Alnus sp.

(?), 12.IX.1990 Larsson 7447 (GB), Blagodatnoe, Alnus sp.,

23.IX.1990 Larsson 8140 (GB). Tuva: Turgen, Larix sibirica

(charred corticated log), 23.VIII.2014 Kotiranta 26776*(H).

Spain. Burgos: Ordun, Fagus sylvatica, 12.XI.1977 Ryvarden

15329 (O, H). Santander: Cavadonga, Sambucus, 14.IX.1977

Ryvarden 15365 (O, H). Ukraine. Donetsk Reg.: Slovyansk

Dist., Pyskunkivka, Salix alba, 20.XI.2010 Akulov (CWU

4704*). USA. Massachusetts: Hampshire Co., South

Hadley, decayed wood, 4.V.2013 Miettinen 16083*(H);

Worcester Co., Holden, cut bole, 26.IX.2011 Miettinen

14813.2*(H),Worcester,?Acer saccharum, 8.IX.2013

Miettinen 16834 (H), Populus tremuloides, 5.X.2013

Miettinen 17267.4 (H), Quercus sp., 6.X.2013 Miettinen

17272*(H),Acer sp., 26.X.2014 Miettinen 19035 (H).

Michigan: Barry Co., Yankee Springs, Quercus sp.,

3.IX.1955 Cain (H ex TRTC 31857). Tennessee: Cocke

Co., Cosby, decayed wood, 13.VII.2004 K.H. Larsson

12198 (GB), 14.VII.2004 K.H. Larsson 12216 (GB),

17.VII.2004 K.H. Larsson 12282*, 12297*(GB).

Table 2 (continued)

Species/specimen L′LW′WQ′Qn

holotype (4.1) 4.2–5.3 (5.8) 4.73 (2.5) 2.6–3.0 2.79 (1.5) 1.6–1.8 (1.9) 1.70 30

Spirin 8804 (4.0) 4.1–5.0 (5.1) 4.37 (2.5) 2.6–3.1 (3.2) 2.86 1.4–1.8 (1.9) 1.53 30

S. mendax (4.0) 4.2–7.0 (7.2) 5.27 (2.4) 2.5–3.5 (3.6) 2.93 (1.3) 1.4–2.1 (2.3) 1.80 180

holotype (4.7) 4.8–6.2 5.60 (2.7) 2.9–3.5 (3.6) 3.09 (1.6) 1.7–2.1 (2.3) 1.82 30

Larsson 12022 (4.6) 4.8–5.6 5.12 (2.6) 2.7–3.0 (3.1) 2.85 (1.6) 1.7–1.9 1.80 30

Nordén 9579 (4.7) 4.8–5.8 (6.0) 5.33 (2.6) 2.7–3.1 (3.2) 2.93 (1.6) 1.7–2.0 (2.1) 1.82 30

Spirin 10060 (5.0) 5.1–7.0 (7.2) 5.71 (2.6) 2.7–3.2 (3.3) 2.93 1.7–2.3 (2.4) 1.95 30

Spirin 10107 (4.2) 4.3–5.9 (6.1) 5.11 (2.7) 2.8–3.2 (3.5) 3.00 (1.3) 1.4–1.9 (2.0) 1.71 30

Vlasák 1110/14.1 (4.0) 4.2–5.4 (5.5) 4.75 (2.4) 2.5–3.0 2.76 (1.4) 1.5–1.9 1.72 30

S. rigidum (3.8) 4.0–5.1 (5.2) 4.44 2.0–2.5 (2.7) 2.22 (1.6) 1.7–2.2 (2.3) 2.01 30

holotype (3.8) 4.0–5.1 (5.2) 4.44 2.0–2.5 (2.7) 2.22 (1.6) 1.7–2.2 (2.3) 2.01 30

S. suecicum (4.1) 4.2–6.2 (6.3) 4.90 (2.1) 2.2–3.1 (3.2) 2.53 (1.5) 1.6–2.4 (2.5) 1.93 180

holotype (4.8) 5.1–6.2 (6.3) 5.55 (2.4) 2.5–3.1 (3.2) 2.80 (1.7) 1.8–2.2 (2.3) 1.99 30

Kunttu 5959 (4.1) 4.2–5.2 4.70 2.2–2.8 (2.9) 2.52 (1.6) 1.7–2.1 (2.2) 1.88 30

Larsson 11849 (4.1) 4.2–5.7 (5.8) 4.91 (2.1) 2.2–2.9 2.42 (1.7) 1.8–2.4 (2.5) 2.05 30

Miettinen 11044 (4.5) 4.6–5.9 (6.1) 5.12 2.2–2.9 (3.0) 2.50 (1.7) 1.8–2.3 (2.5) 2.06 30

Miettinen 14550.1 (4.1) 4.2–5.1 (5.3) 4.60 2.2–2.9 (3.0) 2.52 (1.5) 1.6–2.0 (2.1) 1.83 30

Spirin 8932 (4.1) 4.2–5.3 (5.8) 4.56 (2.1) 2.2–2.9 (3.0) 2.42 (1.7) 1.8–2.1 (2.2) 1.89 30

S. vigilans (6.1) 6.3–11.2 (11.4) 8.68 (3.0) 3.1–5.4 (6.2) 4.35 (1.6) 1.7–2.5 (2.6) 2.01 150

holotype (7.0) 7.2–9.1 (9.4) 8.09 (3.9) 4.0–5.2 (5.8) 4.49 (1.6) 1.7–2.0 (2.1) 1.81 30

Eriksson 9106 (8.0) 8.3–10.5 (10.6) 9.34 (3.8) 4.0–5.0 (5.1) 4.44 (1.8) 1.9–2.2 (2.3) 2.11 30

Fonneland 2011-77 (8.1) 8.8–11.2 (11.4) 9.95 (4.0) 4.1–5.1 (5.2) 4.50 (1.8) 1.9–2.5 (2.6) 2.22 30

Häyrén 1934 (7.7) 7.8–10.3 (10.9) 8.61 (4.1) 4.2–5.4 (6.2) 4.69 (1.7) 1.8–2.0 (2.1) 1.84 30

Spirin 8778 (6.1) 6.3–8.8 (8.9) 7.43 (3.0) 3.1–4.3 (4.5) 3.64 (1.7) 1.8–2.3 (2.4) 2.05 30

Fig. 7 Microscopic structures of S. jacksonii (Svantesson 699): hyphae,

hymenial cells, and basidiospores

464 Mycol Progress (2021) 20:453–476

Sertulicium jacksonii (Liberta) Spirin & K.H. Larss.,

comb. nov.—Figs. 7and 10

MB 833944

≡Paullicorticium jacksonii Liberta, Brittonia 14: 223,

1962. Holotype. Canada. Ontario: York, Maple, decayed

wood, 11.IX.1943 Jackson (TRTC 18722, studied).

Basidiocarps effused, pruinose, hardly visible by the naked

eye, 0.02–0.03 mm thick. Hymenial surface whitish, smooth

or porulose. Margin indistinct.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae sparse, randomly arranged, slightly to moderately

thick-walled, branched mostly at sharp angles, often anasto-

mosing, (2.2–)2.3–6.4 (–6.8) μm in diam. (n = 68/5).

Subhymenial hyphae thin- or slightly thick-walled, densely

and randomly arranged, (2.0–) 2.1–3.8 (–4.0) μm in diam.

(n = 100/5). Hyphidia occasionally present, simple, slightly

projecting, 3–4μm in diam. Basidia clavate, 4–6-spored,

gradually tapering to the basal part, (11.6–) 12.2–23.8 (–

24.7) × (5.8–)5.9–9.3 (–9.4) μm (n = 72/4), a few pleural

basidia seen. Basidioles broadly clavate to subglobose,

(8.2–)8.3–13.2 (–13.3) × (4.7–)5.7–9.2 (–9.3) μm (n = 35/

4). Basidiospores cylindrical to narrowly ellipsoid, straight or

slightly curved, longest spores slightly tapering to the distal

end, (5.1–)5.2–8.2 (–8.6) × (2.7–)2.8–4.1 (–4.2) μm(n=

170/6), L = 6.08–7.13, W = 2.99–3.66, Q = 1.79–2.39.

Remarks.Paullicorticium jacksonii was described from

Canada but later rarely treated as a species of its own.

Eriksson et al. (1978)placedP. jacksonii among the syno-

nyms of Sistotremastrum niveocremeum, and the species has

been interpreted that way up to the present moment. Our data

confirm that P. jacksonii is a good species belonging to

Sertulicium. In addition to the type collection, we studied

specimens from the USA and Europe.

Sertulicium jacksonii belongs to a difficult complex of

extremely thin, conifer-dwelling species hardly distinguish-

able via morphological traits. Among them, S. jacksonii can

be recognized by its wide subicular hyphae with variably

thickened walls. Two similar-looking species, Sertulicium

vernale and S. lateclavigerum, have narrower subicular hy-

phae than those of S. jacksonii. Additionally,

S. lateclavigerum possesses narrower basidiospores than

in the other two species (Table 2). However, the differences

listed here were detected from a very restricted set of spec-

imens. Further studies with broader sampling may improve

our observations considerably. Paullicorticium ansatum

Liberta, yet another morphologically similar although phy-

logenetically unrelated species, may be easily separated

from Sertulicium spp. due to ansiform (loop-like) clamps

and basidia with up to eight sterigmata.

Specimens examined. Italy. Trentino—Alto Adige:

Bolzano, Picea abies, 30.VIII.1990 Bernicchia 5464 (O

ex HUBO). Norway. Oppland: Jevnaker, P. abies,

4.X.2011 Svantesson 699* (O). Russia. Karelia:

Medvezhiegorsk Dist., Krivozero, P. abies, 19.VI.1942

Laurila 3256b (H). Leningrad Reg.: Boksitogorsk Dist.,

Kolp’,P. abies, 28.VII.2016 Spirin 10425* (H). USA.

New York: Essex Co., Arbutus Lake, Abies sp.,

22.IX.2013 Miettinen 17141* (H).

Sertulicium lateclavigerum (Boidin & Gilles) Spirin &

Viner, comb. nov.—Fig. 8

MB 833945

≡Sistotremastrum lateclavigerum Boidin & Gilles, Bull.

Soc. Mycol. France 110: 217, 1994. Holotype. France.

Landes: Tartas, Pinus pinaster (fallen branch), 17.VI.1988

Gilles 765* (LY-JB 13467, studied).

Basidiocarps effused, pruinose, rather loose or compact,

covering a few cm, 0.02–0.05 mm thick. Hymenial surface

cream-colored, smooth or porulose. Margin indistinct.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae sparse, randomly arranged, thin- or only slightly

thick-walled, branched mostly at sharp angles, often anasto-

mosing, (2.2–)2.3–4.3 (–4.9) μm in diam. (n = 40/2).

Subhymenial hyphae thin-walled (wall distinct), rather loosely

and randomly arranged, (2.0–)2.1–3.7 (–2.8) μmindiam.(n

= 40/2). Cystidia occasionally present, thin-walled, easily col-

lapsing, broadly clavate or subglobose, 19–33 × 9–16.5 μm.

Hyphidia occasionally present, embedded, simple, 2–2.5 μm

in diam. Basidia clavate, 4–6-spored, gradually tapering to the

basal part, (9.3–)9.9–20.7 (–21.2) × (4.4–)4.8–9.3 (–11.1)

μm (n = 40/2), a few pleural basidia seen. Basidioles broadly

clavate to bladder-shaped or subglobose, (7.3–)7.9–10.2 (–

10.3) × (4.4–)5.4–6.6 (–7.9) μm (n = 20/1). Basidiospores

cylindrical to subfusiform, sometimes slightly curved, (4.3–)

Fig. 8 Microscopic structures of S. lateclavigerum (holotype). aHyphae

and hymenial cells. bBasidiospores

465Mycol Progress (2021) 20:453–476

4.6–7.2 (–7.3) × (2.1–)2.2–3.2 μm (n = 60/2), L = 5.32–5.82,

W = 2.57–2.84, Q = 2.05–2.09.

Remarks.Sistotremastrum lateclavigerum was described

based on a single collection from France. The diagnostic fea-

tures treated in the protologue were the bubble-like cystidia,

basidia with up to 8 sterigmata and rather narrow and slightly

curved basidiospores (Boidin and Gilles 1994). Sequences

obtained from the holotype were published by Gruhn et al.

(2018). They indicate that the species belongs to Sertulicium

and it is not closely related tothe similarly looking S. jacksonii

and S. vernale. Morphological differences of

S. lateclavigerum versus the two latter species are presented

under S. jacksonii.Paullicorticium allantosporum J. Erikss.

has basidiospores similar to S. lateclavigerum,(5.2–)5.3–7.2

×(2.3–)2.4–3.2 (–3.3) μm (n = 30/1), L = 6.10, W = 2.79, Q =

2.20, but they are more clearly curved and have large oil

droplets in the cytoplasm. Moreover, basidia of

P. allantosporum are 6–8-sterigmatic, with a clearly

contracted and more or less sinuous basal part.

We studied the holotype of S. lateclavigerum and observed

basidia with 4–6 sterigmata only. In our opinion, the presence

of globose or broadly clavate cystidia-like cells is insufficient

as a single diagnostic character in Sistotremastrum s. l. We

observed hymenial cells of the same shape inone collection of

S. jacksonii (Laurila 3256b), in S. niveocremeum (Van

Autgaerden S-20), as well as in three representatives of

Sistotremastrum s. str. (holotype of S. geminum and two se-

nescent collections of S. mendax and S. vigilans,respectively).

On the other hand, another collection of S. lateclavigerum

studied by us (Spirin 13457) is totally devoid of cystidia-like

cells.

So far, S. lateclavigerum has been collected in France and

Slovenia. However, environmental sequences in GenBank

and UNITE point to a broader distribution area of this species.

One of them came from Vietnam (MF942562) while the sec-

ond (UDB051695) is from Estonia.

Specimens examined. Slovenia. Gorenjska: Mojstrana,

Triglavska Bistrica, P. abies, 28.IX.2019 Spirin 13457*(H).

Sertulicium niveocremeum (Höhn. & Litsch.) Spirin &

K.H. Larss., comb. nov.—Fig. 10

MB 833946

≡Corticium niveocremeum Höhn. & Litsch., Sitzungsb.

Kaiserl. Akad. Naturwiss. Mat.-Naturwiss. Klasse I

117:1117, 1908. Holotype. Austria. Niederösterreich: Wien-

Umgebung, Unter-Tullnerbach, Fagus sylvatica,11.III.1905

Höhnel (W 16251, studied).

=Galzinia vesana Boidin & Gilles, Bull. Soc. Mycol.

France 106: 158, 1990. Holotype. France. Landes: St.

Perdon, Quercus pedunculata,2.III.1989Gilles 828 (LY-JB

13675, studied).

Basidiocarps effused, initially pruinose, later compact, cov-

ering several cm, 0.03–0.1 mm thick. Hymenial surface

whitish to cream-colored or pale ochraceous, smooth or

porulose. Margin first pruinose, later compact and sharply

delimited.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae interwoven to subparallel, slightly thick-walled,

branched mostly at right angles, (3.6–)3.7–5.3 (–5.6) μmin

diam. (n = 40/2); some hyphae inflated at septa up to 6 μmin

diam. Subhymenial hyphae thin- or slightly thick-walled,

densely arranged, some short-celled and slightly inflated,

(2.2–)2.3–4.3 (–4.5) μm in diam. (n = 80/4). Hyphidia occa-

sionally present, embedded, simple, 2.5–4.5 μmindiam.

Basidia clavate, 4–6-spored, gradually tapering to the basal

part, (10.7–)10.8–24.3 (–26.7) × (5.1–)5.2–8.3 (–8.4) μm

(n = 60/3), somebasidia slightly thick-walled at the basal part.

Basidioles broadly clavate to bladder-shaped or subglobose,

(7.2–)8.4–14.3 (–14.7) × (4.1–)4.2–8.3 (–8.4) μm (n = 80/4).

Basidiospores cylindrical, straight or slightly curved, (5.2–)

5.5–8.6 (–9.8) × (2.6–)2.7–4.2 (–4.3) μm (n = 120/4), L =

6.55–7.46, W = 3.08–3.46, Q = 1.97–2.24.

Remarks.Sertulicium niveocremeum is distributed in

temperate—boreal Eurasia. It inhabits angiosperm hosts,

mainly still attached or recently fallen branches but it may

occur also on rather rotten wood. For a long time,

S. niveocremeum has been mixed up with another

angiosperm-dwelling species, S. granuliferum; their differ-

ences are discussed under the latter species. We studied the

type material and a recent collection of Galzinia vesana from

France; in our opinion, it is merely a monstrous form of

S. niveocremeum with unusually long basidia and

basidiospores, as well as occasionally branched sterigmata.

DNA data from recently collected specimens confirmed this

synonymy. While introducing G. vesana, Boidin and Gilles

(1990) referred to a description and illustration of Galzinia sp.

from Sweden (Eriksson and Ryvarden 1975: 398) as another

possible record of that species. We re-checked the specimen

illustrated by Eriksson and concluded that it belongs to

Sertulicium, being morphologically most similar to

S. niveocremeum. However, its exact identity is still uncertain,

and it is therefore treated as Sertulicium sp. 2 under Specimens

examined.

Some specimens of S. niveocremeum collected in the win-

ter or spring are dominated by four-sterigmatic basidia. Only a

few 5–6-sterigmatic basidia were detected in such specimens

after meticulous study. Moreover, these collections usually

have longer basidiospores than in most other specimens of

S. niveocremeum (in particular, reaching 14.5 μm long in

specimen Van Autgaerden S-20) and thus can be mixed up

with Sistotremastrum vigilans. The latter species, introduced

below, has constantly four-sterigmatic basidia and it occurs

exclusively on coniferous hosts while S. niveocremeum seems

to be restricted to angiosperms.

Specimens examined. Belgium. Antwerpen: Zoersel,

Zoerselbos, deciduous wood, 16.V.2019 Van Autgaerden

466 Mycol Progress (2021) 20:453–476

S-20* (GENT). Oost-Vlaanderen: Kluisbergen, Kluisbos, de-

ciduous wood, 20.II.2017 Schoutteten 17-001 (GENT),

13.III.2017 Schoutteten 17-202 (GENT). Finland. Varsinais-

Suomi: Lohja, Tamminiemi, Corylus avellana, 5.XI.2020

Spirin 14241 (H). Uusimaa: Helsinki, Veräjämäki, Sorbus

aucuparia (?), 19.X.2011 Miettinen 14925.3* (H). Etelä-

Häme: Kangasala, Lorunkorpi, Salix sp., 23.III.2009

Söderholm 4050* (H). France. Haut-Rhin: Sainte-Marie-

aux-Mines, Freland, Le Limbach, F. excelsior, 12.X.2019

Spirin 13566 (H). Pyrenées-Orientales: Argelès-sur-Mer, an-

giosperm (twigs), 2.XI.2008 K.H. Larsson 13727*(GB).

Italy. Emilia-Romagna: Bologna, Quercus sp., 3.XI.1983

Bernicchia 1849 (O ex HUBO), 16.X.1984 Ryvarden 22225

(O). Sardinia: Cagliari, 17.III.2003 Arras 897 (H ex HUBO);

Nuoro, Quercus sp., 30.III.2010 Bernicchia 8593 (O ex

HUBO). Russia. Krasnoyarsk Reg.: Turukhansk Dist., Bor,

Alnus sibirica, 16.VIII.2013 Kotiranta 26267* (H). Sakha

Rep.: Nizhnekolymsk Dist., Tsherski, Alnus fruticosa,

18.VIII.1972 Parmasto (H ex TAAM 56632). Spain. Canary

Islands: Tenerife, Las Mercedes, decayed wood, 18.I.1974

Ryvarden 12639 (O, H). United Kingdom. England:

Hampshire, New Forest Nat. Park, F. sylvatica, 5.II.1994

Legon (GB).

Sertulicium vernale Spirin & Volobuev, sp. nov.—Fig. 9

MB 833947

Holotype. Finland. Etelä-Häme: Kangasala, Pikku-Salmus,

61.4138° 23,9275° ±300 m, moist depression in rather old

Picea forest, on a fallen, decorticated Picea abies,

10.V.2007 Söderholm 3886* (H 6003442, isotype—LE).

Etymology.Vernalis (Lat., adj.)—vernal, occurring in the

spring.

Basidiocarps effused, pruinose, rather loose, covering a

few cm, 0.02–0.04 mm thick. Hymenial surface greyish,

smooth or porulose. Margin indistinct.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae sparse, randomly arranged, slightly to moderately

thick-walled, branched mostly at sharp angles, often anasto-

mosing, (2.2–)2.3–4.8 (–5.2) μm in diam. (n = 40/2).

Subhymenial hyphae thin-walled (wall usually distinct), rather

tightly and randomly arranged, (2.0–)2.1–4.1 (–4.2) μmin

diam. (n = 40/2), sometimes bearing bubble-like cells, 10–12

×8–11 μm. Hyphidia rare, embedded, simple, 2.5–3.5 μmin

diam. Basidia clavate, 4–6-spored, gradually tapering to the

basal part, (11.2–)11.8–27.4 (–37.2) × (5.0–)5.1–7.2 (–7.3)

μm (n = 44/2). Basidioles broadly clavate to bladder-shaped

or subglobose, (6.0–)6.9–10.2 (–10.8) × (4.4–)5.2–6.8 (–6.9)

μm (n = 20/1). Basidiospores narrowly ellipsoid to broadly

cylindrical, sometimes slightly curved, (5.7–)5.8–8.2 (–8.3) ×

(2.8–) 2.9–3.8 (–3.9) μm (n = 60/2), L = 6.90–7.02, W =

3.28–3.31, Q = 2.09–2.15.

Remarks.Sertulicium vernale is morphologically very sim-

ilar to S. jacksonii, and it can be differentiated from the latter

species by its narrower subicular hyphae and longer basidia.

The species isso far known from two localities in Finland and

two environmental sequence from Sweden (AY805625—

Menkis et al. 2004) and CO, USA (JX136434—Huffman

et al. 2013). The North American sequence isslightlydifferent

(2 bp) from the two European ones, and it may still belong to

an undescribed sibling species.

Specimens examined. Finland. Varsinais-Suomi: Lohja,

Tamminiemi, P. abies,5.XI.2020Spirin 14244 (H).

Sistotremastrum J. Erikss., Symb. Bot. Upsalienses 16 (1):

62, 1958.

Basidiocarps effused, thin to rather substantial (up to

0.2 mm thick), pruinose to waxy-compact. Hymenophore

smooth, warted or odontioid-semiporoid. Hyphal structure

monomitic; all hyphae clamped, CB (+), easily collapsing,

in odontioid species with a more or less clear difference be-

tween trama and subhymenium. Cystidia absent in all but one

species, hyphidia present, simple or accidentally branched.

Basidia clavate or suburniform, with 2–4or4–6 sterigmata,

usually collapsing at the apex, senescent basidia often slightly

thick-walled at the base. Basidiospores thin-walled (but the

wall distinct), narrowly ellipsoid or ovoid to cylindrical,

inamyloid, acyanophilous, contents homogeneous and CB

(+). On rotten wood of deciduous trees and conifers.

Generic type. Sistotremastrum suecicum Litsch. ex J.

Erikss.

The genus is redefined here to exclude members of the

Sistotremastrum niveocremeum complex subsumed under

Sertulicium. Differences between the two genera are discussed

above. Extending Sistotremastrum s. str. with a number of four-

Fig. 9 Microscopic structures of S. vernale (holotype): hyphae, hymenial

cells, and basidiospores

467Mycol Progress (2021) 20:453–476

sterigmatic taxa makes it difficult to delimit the genus from

Brevicellicium and from smooth-spored Trechispora species.

Trechispora differs by generally soft basidiocarps, short, often

almost isodiametric subhymenial cells, and presence of

ampullate septa on subicular hyphae. Brevicellicium species have

similar subhymenial cells as in Trechispora but lack ampullate

septa in the subiculum, which is poorly developed. Moreover,

basidia in the four-sterigmatic Sistotremastrum spp. are more or

less clearly suburniform, i.e., slightly constricted at the middle

and narrowed at the apical part (except S. vigilans with excep-

tionally long, clavate-utriform basidia) while they are barrel-

shaped or short-clavate in Brevicellicium and Trechispora.

All but one four-sterigmatic representatives of the genus

treated below are distributed in tropical areas. However, two

unnamed sequences (CMH343, GenBank KF800434;

6S1.10.S04, GenBank EF619877) originated from the eastern

part of the USA (Fig. 4). This could point towards more

undescribed taxa in the four-sterigmatic species complex dis-

tributed in geographic regions with a cooler climate.

Sistotremastrum aculeatum Miettinen & Viner, sp.

nov.—Fig. 10

MB 833948

Holotype. Indonesia. Sumatera Barat: Kab. Lima Puluh

Kota, Gunung Sago, -0.30585° 100.67762°, alt. 1400 m, low-

er montane rainforest, on a fallen log of dicot (decay stage

3/5), 25.VII.2009 Miettinen 13799.1* (ANDA—holotype, H

7009306—isotype).

Etymology.Aculeatus (Lat., adj.)—aculeate.

Basidiocarps effused, first soft-floccose, then rather tough,

covering several to tens of cm, 0.1–0.2 mm thick. Hymenial

surface pale cream-colored to pale ochraceous, first warted,

then odontioid, with irregularly arranged, sharp-pointed, part-

ly fusing spines, 2–3 per mm, up to 2 mm long, or semiporoid,

with shallow pores 0.5–1 per mm. Margin white to pale

ochraceous, compact, in some portions with thin, white, pro-

nounced hyphal strands. Smooth areas between spines fertile.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae unevenly thick-walled, (2.8–)2.9–5.1 (–5.2) μmin

diam. (n = 40/2), often in subparallel bundles. Tramal hyphae

distinctly thick-walled, rather tightly arranged, interwoven to

subparallel, sometimes glued together, (2.7–)3.0–5.6 (–6.2)

μm in diam. (n = 40/2). Subhymenial hyphae slightly thick-

walled, short-celled, (2.3–)2.4–4.2 (–4.6) μm in diam. (n =

40/2), rarely inflated up to 6 μm. Rhomboid or prismatic crys-

tals occasionally present among subicular or tramal hyphae,

up to 9 μm in widest dimension, solitary or in large groups.

Hyphidia occasionally present, embedded or slightly

projecting, simple, 2–3μm in diam. Basidia suburniform, 2–

4-spored, (7.3–)7.7–12.2 (–12.3) × (3.3–)3.4–4.5 (–5.2) μm

(n = 30/2), senescent basidia slightly thick-walled at the basal

part. Basidioles clavate to bladder-shaped, 5.4–8.2 × 3.2–

4.3 μm (n = 10/1). Basidiospores cylindrical to narrowly

ovoid, straight, (4.1–)4.2–6.2 (–6.8) × (2.1–)2.2–3.1 (–3.3)

μm (n = 120/3), L = 4.98–5.07, W = 2.50–2.65, Q = 1.94–

2.03.

Remarks.Sistotremastrum aculeatum seems to be widely

distributed in South-East Asia from China to Sumatra.

Morphologically, it is most similar to the South American

S. aculeocrepitans. It differs from the latter species mainly

by longer spines, which tend to fuse together and produce

shallow, wide pores.

Specimens examined. China. Yunnan: Xishuangbanna,

Mandian Waterfalls, hardwood (?), 17.VIII.2005 Miettinen

10380.1* (H). Indonesia. Riau: Indragiri Hulu, Daerah

Sungai Denalo, dead polypore, 2.VII.2004 Miettinen 8829

(H). Thailand. Phang Nga: Kurabari, Kura Andaman Private

Beach, hardwood, 3.II.2015 Dunaev KUN1105* (H).

Singapore. Yishun, Nee Soon pipeline, hardwood,

17.III.2020 Miettinen 23533* (SING, H).

Sistotremastrum aculeocrepitans Gruhn & Alvarado,

Phytotaxa 379: 32, 2018.—Fig. 10

Basidiocarps effused, compact, covering several cm, 0.1–

0.2 mm thick. Hymenial surface cream-colored to pale

ochraceous, odontioid; spines densely arranged, 3–4per

mm, up to 0.3 mm long, sharp-pointed, sometimes fusing

together and then fimbriate. Margin white to pale cream-col-

ored, adnate, producing abundant thin, short, white hyphal

strands. Smooth areas between spines fertile.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae interwoven, distinctly thick-walled, branched mostly

at sharp angles, (3.4–)3.8–5.7 (–6.0) μm in diam. (n = 20/1).

Tramal hyphae distinctly thick-walled, densely arranged and

Fig. 10 Basidiospores of Sertulicium and Sistotremastrum spp. a

Sertulicium granuliferum (Miettinen 14813.2). bSertulicium jacksonii

(three left—holotype, three right—Svantesson 699). cS. niveocremeum

(holotype). dSistotremastrum aculeatum (holotype). eS. aculeocrepitans

(K.H. Larsson 16097). fS. confusum (holotype). gS. denticulatum (ho-

lotype). hS. fibrillosum (K.H. Larsson 16988)

468 Mycol Progress (2021) 20:453–476

partly glued together, (2.8–)2.9–4.8 (–5.2) μm in diam. (n =

20/1), in subhymenium more or less vertically oriented, thin-

or slightly thick-walled, short-celled and slightly inflated,

(2.9–)3.1–4.8 (–4.9) μm (n = 20/1). Hyphidia abundant, em-

bedded or projecting up to 20 μm, simple, 2–3.5 μmindiam.

Basidia suburniform, 4-spored, (7.7–)8.4–13.8 (–14.2) ×

(4.0–) 4.1–5.0 (–5.2) μm (n = 30/2). Basidioles clavate to

bladder-shaped, 7–9×4–5μm. Basidiospores cylindrical to

narrowly ovoid, straight, a few of the longest spores slightly

lacrymoid, (4.0–)4.1–5.6 (–5.8) × (2.1–)2.2–2.8 (–2.9) μm(n

=60/2),L=4.44–5.10, W = 2.30–2.35, Q = 1.93–2.19.

Remarks. The species was introduced based on specimens

from Martinique and French Guiana (Gruhn et al. 2018). We

collected it in Brazil, and these specimens are the source of

the present description. Differences of S. aculeocrepitans

from S. denticulatum are treated under the latter species.

Another similar-looking species from South America,

S. fibrillosum Gruhn & Alvarado, has soft basidiocarps and

densely arranged spines covering hyphal strands, and also

considerably longer basidia. Sistotremastrum aculeocrepitans

is reported here as new to Brazil.

Specimens examined. Brazil. Paraíba: Areia, Reserva Mata

do Pau-Ferro, angiosperm, 28.IV.2013 K.H. Larsson 16097*

(URM, O). Pará: Belém, Museu Goeldi, Campus de Pesquisa,

angiosperm, 25.XI.2013 K.H. Larsson 16478*(MG,O).

Sistotremastrum confusum K.H. Larss. & Spirin, sp.

nov.—Fig. 10

MB 833949

Holotype. Brazil. Pernambuco: Jaqueira, Reserva

Particular do Patrimônio Natural Frei Caneca, Barragem das

Moças, -8.720420° -35.843436°, on rotten angiosperm wood,

20.IV.2013 Larsson 16023* (URM, isotype—O).

Etymology.Confusus (Lat., adj.)—confusing.

Basidiocarps effused, soft, covering several cm, 0.04–

0.07 mm thick. Hymenial surface whitish to cream-colored,

smooth or irregularly tuberculate, accidentally cracking in old

basidiocarps. Margin first arachnoid, with well-visible thin

hyphal strands, later compact and rather clearly delimited.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae interwoven to subparallel, slightly thick-walled, irreg-

ularly branched, (2.2–)2.3–4.2 (–4.8) μm in diam. (n = 40/2).

Subhymenial hyphae thin- or slightly thick-walled, rather

loosely arranged, some short-celled and slightly inflated,

(2.4–)2.6–4.2 (–4.8) μm in diam. (n = 40/2). Hyphidia rarely

present, embedded or only slightly projecting, simple, 3–

3.5 μm in diam. Basidia clavate, 4-spored, gradually tapering

to the basal part, (12.2–)13.1–25.0 (–28.8) × (4.3–)4.4–6.2 (–

6.3) μm (n = 22/2). Basidioles clavate to bladder-shaped,

(7.3–)7.4–11.8 (–13.0) × (4.2–)4.3–5.3 (–6.0) μm (n = 20/

2). Basidiospores cylindrical to narrowly ellipsoid or narrowly

ovoid, (5.3–)5.7–7.6 (–7.9) × 2.9–3.9 (–4.0) μm (n = 60/2), L

=6.54–6.57, W = 3.16–3.32, Q = 1.99–2.07.

Remarks.Sistotremastrum confusum is introduced here

based on two sequenced collections from Brazil.

Morphologically, it is most similar to S. vigilans distributed

in Northern Hemisphere. The latter species has considerably

larger basidia and basidiospores than those of S. confusum.

Specimens examined. Brazil. Pernambuco: Jaqueira,

Reserva Particular do Patrimônio Natural Frei Caneca,

Barragem das Moças, angiosperm, 20.IV.2013 K.H. Larsson

16004* (URM, O).

Sistotremastrum denticulatum Motato-Vásquez & Spirin,

sp. nov.—Fig. 10

MB 833950

Holotype. Brazil. Saõ Paulo: Iguape, Juréia-Itatins Ecological

Station, -24.417° -47.372°, fallen branch, 19.II.2017 Motato-

Vásquez 894* (SP 467087, isotype—H 7009716).

Etymology.Denticulatus (Lat., adj.)—denticulate.

Basidiocarps effused, soft, waxy covering several cm,

0.05–0.1 mm thick. Hymenial surface cream-colored to pale

ochraceous, odontioid; spines densely arranged, 5–6 per mm,

up to 0.5 mm long, rather blunt-pointed, sometimes fusing

together and then fimbriate. Margin white to pale cream-col-

ored, adnate, arachnoid, producing abundant thin, short, white

hyphal strands. Smooth areas between spines fertile.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae interwoven to subparallel, distinctly thick-walled,

branched mostly at sharp angles, (2.6–)3.2–5.2 (–5.4) μmin

diam. (n = 20/1). Tramal hyphae interwoven to subparallel,

distinctly thick-walled, rather loosely arranged, (3.1–)3.2–4.2

(–4.8) μm in diam. (n = 20/1), in subhymenium more or less

vertically oriented, thin- or slightly thick-walled, mostly short-

celled and slightly inflated, (2.2–)2.3–3.8 (–4.1) μm (n = 20/

1). Hyphidia abundant, mostly slightly projecting, simple, 2–3

μm in diam. Basidia suburniform to almost clavate, (1–)2–4-

spored, (6.7–)7.2–12.2 (–12.3) × (3.7–)3.8–4.8 (–5.0) μm(n

= 20/1). Basidioles clavate to subglobose, (4.8–)5.2–7.2 (–

7.6) × (3.5–) 3.8–4.8 (–4.9) μm (n = 20/1). Basidiospores

narrowly ellipsoid to broadly cylindrical, straight, a few of

the longest spores somewhat fusiform, (3.9–)4.0–5.3 (–5.4)

×(2.0–)2.1–3.0 (–3.1) μm (n = 30/1), L = 4.51, W = 2.48, Q =

1.83.

Remarks.Sistotremastrum denticulatum is morpholog-

ically most similar to S. aculeocrepitans butithasmore

densely arranged spines fusing together in characteristic

fimbriate groups. Microscopically, these species are al-

most identical except for loosely arranged and not ag-

glutinated hyphae in S. denticulatum.Sistotremastrum

fibrillosum has spines not only on the hymenial surface

but also on hyphal cords while S. denticulatum has ster-

ile hyphal strands. The species is so far known only

from the type locality in the southern part of Brazil.

469Mycol Progress (2021) 20:453–476

Sistotremastrum fibrillosum Gruhn & Alvarado,

Phytotaxa 379: 31, 2018—Fig. 10

Basidiocarps effused, soft, covering several cm, 0.05–

0.1 mm thick. Hymenial surface cream-colored, odontioid;

spines densely arranged, 6–9 per mm, up to 0.4 mm long,

sharp-pointed, often fusing together in fascicles of 2–4, cov-

ering also hyphal strands. Margin white to pale cream-colored,

floccose or radially fibrillose. Hyphal strands well developed,

sometimes a few cm long and up to 0.5 mm thick.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae mostly subparallel, distinctly thick-walled, branched

mostly at sharp angles, (3.3–)3.6–6.2 (–7.1) μm in diam. (n =

20/1); some hyphae encrusted by densely distributed

subglobose resinous globules. Tramal hyphae with unevenly

thickened walls, rather loosely arranged, subparallel to inter-

woven, (3.2–)3.3–4.3 (–4.6) μmindiam.(n=20/1),in

subhymenium more or less vertically oriented, thin- or slightly

thick-walled, sometimes short-celled and slightly inflated,

(1.7–)2.0–3.2 (–3.6) μm (n = 20/1). Hyphidia present, em-

bedded or projecting up to 20 μm, simple, 1.5–2μmindiam.

Basidia suburniform, 4-spored, (9.4–) 10.3–19.2 (–20.8) ×

(4.0–) 4.1–4.8 (–5.1) μm (n = 20/1). Basidioles clavate to

bladder-shaped, 7–10 × 3.5–4.5 μm. Basidiospores cylindri-

cal to narrowly ellipsoid, straight, (4.0–)4.2–5.2 (–5.6) ×

(2.1–)2.2–2.9 (–3.0) μm (n = 20/1), L = 4.72, W = 2.53, Q

= 1.88, often glued together in large groups.

Remarks. The description above is based on a single spec-

imen from Brazil. Sistotremastrum fibrillosum was originally

introduced from four specimens collected in French Guiana

(Gruhn et al. 2018). However, available DNA sequences show

considerable variation, and this may indicate S. fibrillosum in

the current sense is a collective species. More material is need-

ed to find a more solid solution. Morphological differences of

S. fibrillosum from S. aculeocrepitans detected in the same

geographic region are treated under the latter species.

Specimens examined. Brazil. Pará: Melgaço, Caxiuanã,

ICMBIO headquarter, angiosperm, 13.III.2015 K.H. Larsson

16988* (MG 213771, O).

Sistotremastrum geminum Miettinen & Spirin, sp. nov.—

Figs. 11 and 12

MB 833951

Holotype. Indonesia. Papua Barat: Manokwari Reg.,

Saukorem, Tamuk, -0.5832° 133.14845°, hilly lowland pri-

mary rainforest, on an uprooted Intsia bijuga (150 cm in di-

ameter, decay stage 1-4/5), 30.X.2010 Miettinen 14333.2*

(MAN, isotype—H7009307).

Etymology.Geminus (Lat., adj.)—similar.

Basidiocarps effused, soft-floccose, covering several cm,

0.07–0.1 mm thick. Hymenial surface pale cream-colored,

grandinioid, with irregularly arranged, obtuse warts 7–8per

mm. Margin pale cream-colored, floccose, partly detaching.

Hyphal strands abundant in the underlying substrate, white

and richly branched. Smooth areas between warts fertile.

Fig. 11 Basidiospores of

Sistotremastrum spp. a

S. geminum (holotype). b

S. induratum (holotype). c

S. mendax (three left—holotype,

three right—Spirin 10060). d

S. rigidum (holotype). e

S. suecicum (holotype). f

S. vigilans (three left—Spirin

10097, two right—holotype)

Fig. 12 Microscopic structures of S. geminum (holotype). aCrystals from

subhymenial hyphae. bSubhymenial hyphae and hymenial cells. c

Subicular hyphae

470 Mycol Progress (2021) 20:453–476

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae interwoven to subparallel, slightly thick-walled,

(2.3–)2.8–4.8 (–5.2) μm in diam. (n = 20/1). Tramal hyphae

thin-walled, rather loosely arranged, interwoven, as a rule

short-celled and more or less distinctly inflated, (3.0–)3.1–

4.8 (–6.2) μm in diam. (n = 20/1). Subhymenial hyphae thin-

walled, easily collapsing, often short-celled and slightly inflat-

ed or twisted, (2.2–)2.3–3.4 (–3.7) μmindiam.(n=20/1).

Hyphal ends at spine tips thin-walled, short-celled, with occa-

sional short side branches, 3–5μm in diam., usually encrusted

by solitary rhomboid crystals or solid crystalline shields.

Cystidia unevenly distributed, thin-walled, varying from

obtuse-clavate to subglobose, mostly enclosed, 11–22 × 6.5–

9.5 μm. Hyphidia present, embedded or slightly projecting,

simple, 2–3μm in diam. at the apex, sometimes swollen at the

base up to 4 μm in diam. Basidia suburniform, 4-spored,

(7.8–)8.0–11.2 (–11.8) × (3.6–)3.7–4.4 (–4.6) μm (n = 20/

1), senescent basidia slightly thick-walled at the basal part.

Basidioles bladder-shaped to subglobose, (4.8–) 4.9–6.8 (–

7.2) × (3.6–) 3.9–4.7 (–5.3) μm (n = 20/1). Basidiospores

cylindricaltonarrowlyellipsoid,straighttoslightlycurved,

(3.8–)3.9–5.2 (–5.5) × (1.9–)2.0–2.6 (–2.9) μm (n = 30/1), L

= 4.28, W = 2.24, Q = 1.92.

Remarks. Hymenophore with short warts (as opposed to

long spines) and thin-walled, loosely arranged tramal hyphae

differentiate S. geminum from other four-sterigmatic represen-

tatives of the genus treated here. The species is so far known

only from the type locality in New Guinea.

Sistotremastrum induratum Spirin, sp. nov.—Fig. 11

MB 833952

Holotype. USA. Washington: Pend Oreille Co., Muskegon

Lake, 48.7923° -117.044°, Abies grandis, 16.X.2014 Spirin

8598* (H 7009717).

Etymology.Induratus (Lat., adj.)—hardening.

Basidiocarps effused, initially pruinose, later compact, cov-

ering several cm, 0.03–0.1 mm thick. Hymenial surface whit-

ish to cream-colored, smooth or porulose. Margin first prui-

nose, later compact and rather sharply delimited. Hyphal

strands present in subiculum of vigorously growing speci-

mens, tough and well-differentiated.

Hyphal structure monomitic; hyphae clamped. Hyphae in

strands densely arranged and partly agglutinated, more or less

parallel, unevenly thick-walled, 5–6μmindiam.Subicular

hyphae interwoven to subparallel, unevenly thick-walled,

branched mostly at right angles, (2.7–)2.8–4.5 (–4.7) μmin

diam. (n = 20/1). Subhymenial hyphae thin- or slightly thick-

walled, densely arranged, some short-celled and slightly in-

flated, (2.8–)3.0–4.8 (–5.0) μm in diam. (n = 40/2). Hyphidia

occasionally present, embedded, simple, 3–5μm in diam.

Basidia clavate, 4–6-spored, gradually tapering to the basal

part, (13.6–)14.0–22.8 (–24.0) × (5.1–)5.2–6.3 (–6.8) μm

(n = 20/1). Basidioles clavate to bladder-shaped, (9.8–)

10.2–15.9 (–16.0) × (3.8–) 3.9–5.3 (–5.7) μm (n = 20/1).

Basidiospores broadly cylindrical to narrowly ovoid, rarely

ellipsoid, (4.0–) 4.1–5.3 (–5.8) × (2.5–) 2.6–3.1 (–3.2) μm

(n=60/2),L=4.37–4.73, W = 2.79–2.86, Q = 1.53–1.70.

Remarks.Sistotremastrum induratum has so far been de-

tected in two localities in the North American North-West. It

is most similar to the European S. mendax but it has on aver-

age shorter basidia and basidiospores, as well as stable differ-

ences in ITS sequences. Distribution areas of the two species

seem not to overlap.

Specimens examined. USA. Washington: Jefferson Co.,

Hoh River, Picea sitchensis,20.X.2014Spirin 8804* (H).

Sistotremastrum mendax Spirin & Volobuev, sp. nov.—

Figs. 5and 11

MB 833953

Holotype. Norway. Telemark: Nome, Mørkvasslia Nat.

Res., 59.288644° 8.865084°, rotten log of Picea abies,

23.IX.2003 K.H. Larsson 12022* (GB).

Etymology.Mendax (Lat., adj.)—deceptive.

Basidiocarps effused, initially pruinose, later compact, cov-

ering several cm, 0.05–0.2 mm thick. Hymenial surface whit-

ishgreytocream-coloredorpaleochraceous,smoothor

porulose, accidentally cracking only in very old basidiocarps.

Margin first pruinose, later compact and rather sharply

delimited. Hyphal strands present in subiculum of vigorously

growing specimens, normally detectable by the naked eye.

Hyphal structure monomitic; hyphae clamped. Hyphae in

strands densely arranged, parallel, slightly thick-walled, 1.5–

2.5 μm in diam. Subicular hyphae interwoven to subparallel,

slightly thick-walled, irregularly branched, (3.1–)3.7–6.2 (–

6.3) μm in diam. (n = 20/1). Subhymenial hyphae thin- or

slightly thick-walled, densely arranged, some short-celled

and slightly inflated, (2.2–)2.3–4.2 (–4.3) μm in diam. (n =

50/3). Hyphidia rarely present, embedded, simple, 3–4μmin

diam. Basidia clavate, 4–6-spored, gradually tapering to the

basal part, (11.4–)11.7–27.2 (–27.3) × (4.6–)4.8–6.6 (–7.2)

μm (n = 50/3). Basidioles clavate to bladder-shaped, (7.2–)

8.2–13.8 (–15.3) × (4.2–)4.3–6.2 (–6.5) μm(n=20/2).

Basidiospores narrowly ellipsoid to broadly cylindrical, some

narrowly ovoid, (4.0–)4.2–7.0 (–7.2) × (2.4–)2.5–3.5 (–3.6)

μm (n = 180/6), L = 4 75–5.71, W = 2.76–3.09, Q = 1.71–

1.95.

Remarks. The species is introduced here as a sibling of

S. suecicum occurring on wood of Picea in Europe. It

differs from S. suecicum s. str. in having broader basidio-

spores and much better developed and easily observable

hyphal strands in subiculum. Moreover, mature

basidiocarps of S. suecicum are cracking in a characteris-

tic way while they mostly stay continuous in S. mendax

(Fig. 2). The host preference alone is not enough to rec-

ognize these species because S. suecicum sometimes oc-

curs on spruce, as well as other coniferous trees. The

471Mycol Progress (2021) 20:453–476

North American S. induratum has on average shorter

basidia and basidiospores than S. mendax (Table 2).

According to our observations, S. mendax prefers old-

growth spruce-dominated forests subjected to minimal (if

any) logging activity. Further ecological studies are needed

to confirm these observations.

Specimens examined. Czech Republic. South Bohemia

Reg.: Boubín Nat. Res., P. abies, 29.X.2011 Vlasák

1110/14.1 (H). Finland. Etelä-Karjala: Miehikkälä, Kaitai,

P. abies, 3.VIII.1976 Fagerström (H). Satakunta: Lamppi,

P. abies, 31.VIII.1939 Laurila (H). Norway. Sør-Trøndelag:

Neadalen, Tydal, P. abies, 24.IX.2011 J. Nordén 9579*(O).

Poland. Podlasie: Hajnówka, Bialowieza NP, P. abies,

23.IX.2019 Miettinen 22476* (H). Russia. Karelia:

Medvezhiegorsk Dist., Krivozero, P. abies, 7.VI.1942

Laurila 3251a, 3258 (H). Leningrad Reg.: Boksitogorsk

Dist., Chagoda, P. abies,9.V.2018Spirin 11887 (H), Kolp’,

P. abies, 8.V.2016 Spirin 10057, 10060 (H), 9.V.2016 Spirin

10086 (H); Podporozhie Dist., Oksboloto, P. abies,

27.V.2017 Spirin 11223 (H), Vazhinka, P. abies, 21.V.2016

Spirin 10107 (H), 4.VI.2016 Spirin 10151 (H), 21.VI.2016

Spirin 10226 (H), 26.V.2017 Spirin 11208 (H), Miettinen

20946*(H),14–15.X.2017 Spirin 11699, 11738 (H).

Sweden. Värmland: Torsby, P. abies, 5.X.2010 J. Nordén

7350 (O).

Sistotremastrum rigidum Motato-Vásquez & Spirin, sp.

nov.—Fig. 11

MB 833954

Holotype. Brazil. Saõ Paulo: Trilha do Mirante, Serra do

Mar State Park, -23.983° -46.7467°, fallen log, 17.XI.2016

Motato-Vásquez 833* (SP 466010, isotype—H).

Etymology.Rigidus (Lat., adj.)—rigid, tough.

Basidiocarps effused, crustaceous, tough, covering sev-

eral cm, 0.05–0.08 mm thick. Hymenial surface almost

white to cream-colored, smooth. Margin white, indistinct-

ly fimbriate, adnate, occasionally with short hyphal

strands.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae tightly glued together, interwoven to subparallel,

thick-walled, hardly visible, 2–4μm in diam. Subhymenial

hyphae slightly to distinctly thick-walled, densely arranged

and partly glued together, some short-celled and slightly in-

flated, (2.0–)2.1–3.0 (–3.2) μm in diam. (n = 20/1). Hyphidia

rarely present, mostly embedded, simple, 2–2.5 μmindiam.

Basidia suburniform to almost clavate, 4-spored, (7.7–)9.2–

14.3 (–16.2) × (4.6–)4.8–6.6 (–7.2) μm (n = 20/1), senescent

basidia slightly thick-walled at the basal part. Basidioles rare,

subglobose, 5–6×4–5μm. Basidiospores cylindrical to

broadly cylindrical, (3.8–) 4.0–5.1 (–5.2) × 2.0–2.5 (–2.7)

μm (n = 30/1), L = 4.44, W = 2.22, Q = 2.01.

Remarks. Basidiocarps of S. rigidum are exceptionally

tough due to densely arrangedand partly agglutinated hyphae,

making the structure resemble species of Phlebia s.l.

However, none of the latter ones forms hyphal strands or has

suburniform basidia with slightly but distinctly thickened

walls. Another four-sterigmatic species with smooth

hymenophore, S. confusum, occurs in Brazil. However, it dif-

fers from S. rigidum in having soft basidiocarps and larger

basidia and basidiospores.

Sistotremastrum suecicum Litsch. ex J. Erikss., Symb.

Bot. Upsalienses 16 (1): 62, 1958—Figs. 5and 11

Holotype. Sweden. Upland: Uppsala, Bondkyrka, “on the

under-side of coniferous fencing-material, lying in a wet spot”

[Pinus sylvestris—identified by Pirkko Harju, H], 4.I.1933

Lundell (Fungi Exsiccati Suecici #464) (S F204406, studied).

Basidiocarps effused, initially pruinose, later waxy, cover-

ing several cm, 0.05–0.2 mm thick. Hymenial surface whitish

to cream-colored or pale ochraceous, smooth or porulose, in

older basidiocarps often cracking into small irregular patches.

Margin first pruinose, later compact and rather sharply

delimited. Hyphal strands present in basal layer of vigorously

growing specimens.

Hyphal structure monomitic; hyphae clamped. Hyphae in

strands densely arranged, parallel, slightly thick-walled, 1.5–

2.5 μm in diam. Subicular hyphae interwoven to subparallel,

slightly thick-walled, branched mostly at right angles, (3.8–)

3.9–5.8 (–6.2) μm in diam. (n = 40/2). Subhymenial hyphae

thin- or slightly thick-walled, densely and randomly arranged,

in subhymenium more or less vertically oriented, some short-

celled and slightly inflated, (2.2–)2.3–4.1 (–4.2) μmindiam.

(n = 100/5). Hyphidia occasionally present, embedded or

projecting (especially in young specimens) up to 15 μmabove

hymenial layer, simple, 2–4μm in diam. Basidia clavate, 4–6-

spored, gradually tapering to the basal part, (10.6–)12.8–26.7

(–26.8) × (4.1–) 4.2–6.2 (–6.3) μm (n = 80/5). Basidioles

clavate to bladder-shaped, (8.3–)8.6–14.2 (–15.1) × (3.3–)

3.8–5.2 (–5.8) μm (n = 20/1). Basidiospores cylindrical to

narrowly ovoid, (4.1–)4.2–6.2 (–6.3) × (2.1–)2.2–3.1 (–

3.2) μm (n = 180/6), L = 4.56–5.55, W = 2.42–2.80, Q =

1.83–2.06.

Remarks.Sistotremastrum suecicum was described

from Sweden (Eriksson 1958) and has so far been treated

in a collective sense, i.e., the name has been used for all

collections from coniferous hosts.Accordingtoourre-

sults, S. suecicum occurs almost exclusively on Pinus

spp.,liketheso-calledkelotreesinNorthEurope

(Niemelä et al. 2002). It is considered an indicator species

of old pine forests of high conservation value in Finland

(Niemelä 2016). Most specimens from other gymnosperm

hosts belong either to S. mendax (in Europe) or to

S. induratum (in the North American North-West).

Differences of S. suecicum from the latter two species

are discussed under S. mendax. The species forms

basidiocarps throughout the year.

472 Mycol Progress (2021) 20:453–476

An ITS sequence of S. suecicum UC2022903 found on

pine wood in California (GenBank KP814148) is clearly dif-

ferent from the rest of the pine-dwelling collections and seem-

ingly representing a species of its own. We leave this problem

until more material from the US Pacific will be available.

Future studies should elucidate if S. suecicum s. str. is also

present in this geographic area or if its distribution in North

America is limited to the east of the Rocky Mountains.

Specimens examined. Canada. British Columbia: Fraser—

Fort George Reg. Dist., Jackman Flats Prov. Park, Pinus

contorta, 25.VII.2015 Spirin 8932* (H). Nova Scotia:

Kentville, Ravine, Pinus resinosa,8.VIII.1954Harrison (H

ex DAOM 52237). Finland. Varsinaissuomi: Parainen,

Kuggö, P. sylvestris, 24.X.2009 Kunttu 5959* (H). Pohjois-

Savo: Heinävesi, Vihtarinniemi, P. sylvestris, 2.X.2006

Miettinen 11044.1* (H). Inarin Lappi: Inari, Piekanavaara,

P. sylvestris, 28.VIII.2008 Miettinen 13310.1 (H). Russia.

Arkhangelsk Reg.: Krasnoborsk Dist., P. sylvestris,

5.VIII.2013 Kotkova (LE 295792*). Krasnoyarsk Reg.:

Turukhansk Dist., Bor, P. sylvestris,24.VIII.2013Kotiranta

26451 (H). Leningrad Reg.: Boksitogorsk Dist., Chagoda,

P. sylvestris, 10.V.2018 Spirin 11888, 11890 (H),

Shidrozero, P. sylvestris, 14.VIII.2014 Spirin 6974 (H);

Podporozhie Dist., Kurba, P. sylvestris, 19.IX.2009 Spirin

3236 (H), Vazhinka, P. abies, 14.X.2017 Spirin 11697 (H).

Nizhny Novgorod Reg.: Arzamas Dist., Pustyn’,P. sylvestris,

13.VIII.2015 Spirin 9227, 9233 (H). Sweden. Jämtland:

Härjedalen, Glumtjärnarna, P. sylvestris, 14.VIII.2011

Miettinen 14550.1* (H). Ångermanland: Resele,

Vignäsbodarna, P. abies (?), 28.VIII.2002 K.H. Larsson

11849* (GB). Jämtland: Härjedalen, Ransjön, P. sylvestris,

14.VIII.2011 Miettinen 14548 (H). USA. Massachusetts:

Worcester Co., Holden, fallen branch, 26.IX.2011 Miettinen

14829*(H),Tsuga canadensis, 21.IV.2013 Miettinen 16061*

(H), Tsuga/Pinus sp., 27.VII.2013 Miettinen 16618*(H).

Sistoremastrum vigilans K.H. Larss. & Spirin, sp. nov.—

Figs. 11 and 13

MB 833955

Holotype. Norway. Vestfold: Stokke, Melsomvik,

59.22541° 10.35202°, rotten log of Picea abies, 30.IV.2011

Fonneland 2011-78* (O).

Etymology.Vigilans (Lat., adj.)—vigilant.

Basidiocarps effused, compact, covering several cm, 0.05–

0.2 mm thick. Hymenial surface white to cream-colored or

pale ochraceous, firstsmooth, in older basidiocarps irregularly

cracking and unevenly tuberculate. Margin first pruinose, later

compact and sharply delimited. Hyphal strands often present,

well-developed, white, occurring in subiculum and sometimes

in the underlying substrate.

Hyphal structure monomitic; hyphae clamped. Subicular

hyphae in parallel bundles or interwoven, with unevenly

thickened walls, randomly branched, some tortuous, with oc-

casional oil-drops, (3.1–)3.2–5.6 (–5.7) μmindiam.(n=60/

3), in older parts with bubble-like inflations 7–10 μmindiam.

Subhymenial hyphae thin- or slightly thick-walled, densely

arranged, some short-celled and slightly inflated, (2.0–)2.2–

4.2 (–5.0) μm in diam. (n = 60/3). Hyphidia occasionally

present, embedded or projecting up to 20 μm, simple or with

accidental side branches, 1.5–5μm in diam. Basidia clavate to

utriform, 4-spored, with widened or tapering bases, (11.3–)

11.4–34.1 (–38.2) × (5.3–) 5.4–8.0 (–8.1) μm (n = 50/3).

Basidiospores narrowly ellipsoid to long cylindrical, straight

or slightly curved, a few lacrymoid or sigmoid, (6.1–)6.3–

11.2 (–11.4) × (3.0–)3.1–5.4 (–6.2) μm (n = 150/5), L = 7.43–

9.95, W = 3.64–4.69, Q = 1.81–2.22.

Remarks.Sistotremastrum vigilans is the only four-

sterigmatic species of the genus so far detected in temperate

and boreal forests of the Northern Hemisphere. It occurs on

coniferous hosts, either late in the season or in spring, and this

might have been a reason for overlooking it. The species is

rare and tends to occur in rather old forests with large-diameter

dead wood.

Sistotremastrum vigilans has the largest basidiospores in

the genus and thus it can be mistaken for a Hyphoderma s. l.

species. Basidia of highly variable size, basidiospores with

homogeneous contents (not guttulate as in Hyphoderma)and

slightly thicker walls, as well as occasionally inflated

subicular hyphae are the most reliable traits for a morpholog-

ical identification of this species. The well-developed hyphal

strands (if present) are another clue to recognizing S. vigilans.

Specimens examined. Canada. Québec: Outaouais,

Gatineau Nat. Park, Abies balsamea, 14.X.1967 Eriksson

9106 (GB,K),conifer,15.X.1967Eriksson 9140,9270,

9279 (GB, K), A. balsamea, 22.X.1967 Eriksson 9281 (GB,

K). Finland. Uusimaa: Helsinki, Laajasalo, P. abies,

25.XI.1934 Häyrén (H), Haltiala, P. abies, 20.XII.2020

Miettinen 24513 (H). Satakunta: Vuorijärvi, P. abies,

6.IX.1937 Laurila (H). Norway. Vestfold: Stokke,

Fig. 13 Microscopic structures of S. vigilans (holotype). aSubhymenial

hyphae and hymenial cells. bSubicular hyphae

473Mycol Progress (2021) 20:453–476

Melsomvik, P. abies, 30.IV.2011 Fonneland 2011-77 (O).

Russia. Leningrad Reg.: Podporozhie Dist., Vazhinka,

P. abies, 21.V.2016 Spirin 10097* (H), 22.V.2016 Spirin

10135 (H). USA. Washington: Jefferson Co., Hoh River,

Tsuga heterophylla, 20.X.2014 Spirin 8778* (H).

Discussion

In this paper, we present the most comprehensive study of

Sistotremastrum to date. Sistotremastrum sensulatonow

holds 18 species, which means that species number more than

doubled. The original concept of Sistotremastrum (Eriksson

1958) contained only two species, S. suecicum and

S. niveocremeum. However, with the much richer sampling

available to us, the phylogenetic analyses prompted us to seg-

regate the species around S. niveocremeum into the new genus

Sertulicium.

Larsson (2007)showedthatSistotremastrum suecicum and

S. niveocremeum belong in the Trechisporales forming a

strongly supported sister clade to the rest of the order.

Larsson (2007) named this clade the Sistotremastrum family

while for the sister clade the name Hydnodontaceae is avail-

able. The same strongly supported topology was recovered by

Gruhn et al. (2018) in a paper where two new Sistotremastrum

species were introduced. In the present work, we were not able

to generate high support values for the node connecting

Sistotremastrum and Sertulicium (Fig. 1). The reason for this

is unclear but probably depends on the generally high diver-

sity of the nuclear ribosomal markers in Trechisporales. We

think it is likely that the concept of Sistotremastrum family as

defined by Larsson will survive, but the question can only be

solved with sequences from an expanded set of genes.

Three species, Sistotremastrum denticulatum,S. geminum,

and S. rigidum, are described based on single specimens.

While we normally would avoid doing this, we found it justi-

fied in these cases. These three species are all well separated in

ITS alignments and differs by 3.6%, 4.6%, and 9.0%, respec-

tively, from their phylogenetically closest relatives (Fig. 1).

Furthermore, all the close relatives of these single-specimen

species are represented by multiple ITS sequences, increasing

confidence that such big ITS differences represent inter- and

not infraspecific variation. All these species are also morpho-

logically clearly separable from their closest relatives. Lastly,

we used distinct distribution areas as a criterion. Distribution

areas of S. denticulatum and S. rigidum do not overlap with

their closest relatives. Difference in distribution areas is not as

clear in the case of S. geminum and its closest relative

S. aculeatum, which are both found in South-East Asia.

However, the latter has been found so far only west of

Wallace’s line (Sumatra and Asian mainland), while

S. geminum east of it, in Australasia (New Guinea).

Other specimens examined

Brevicellicium exile. USA. Washington: Clark Co., Gifford

Pinchot Nat. Forest, T. heterophylla, 11.X.2014 Spirin

8370*(H).

B. olivascens. Russia. Nizhny Novgorod Reg.: Bogorodsk

Dist., Krastelikha, Q. robur, 5.IX.2011 Spirin 4446* (H).

Sweden. Bohuslän: Restenäs, Ulvesund, decaying angio-

sperm branch, 3.X.1998, Larsson 8571*(GB).

B. viridulum. Russia. Sakhalin: Uglegorsk Dist.,

Telnovskoe, Alnus hirsuta,1.IX.2007Kotiranta 29271*(H).

Luellia cystidiata. Denmark. Jylland: Varde, Bordrup

Klitplantage, P. abies,6.X.2009Petersen & Læssøe 13875

(GB).

Paullicorticium allantosporum. Norway. Hedmark: Løten,

Gitvola, P. abies, 26.IX.2018 Spirin 12413 (H).

Pteridomyces galzinii. Italy. Tuscany: Arezzo, Camaldoli

Nat. Res., Polystichum aculeatum, 17.XI.2010 Bernicchia

8122*(GB).

Sertulicium aff. granuliferum. Kenya. Eastern Prov.: Meru,

Chigora, decayed wood, 31.I.1973 Ryvarden 3593 (O); Nyeri,

Regati, decayed wood, 2.II.1973 Ryvarden 9777 (O),

Ryvarden 9888 (O). Tanzania. Tanga Prov.: Tanga Dist.,

Amani, decayed wood, 18.II.1973 Ryvarden 10575 (O, H).

Sertulicium sp. 1. Russia. Khabarovsk Reg.: Khabarovsk

Dist., Ilga, Corylus mandshurica,11.VIII.2012Spirin 5158*

(H).

Sertulicium sp. 2. Sweden. Bohuslän: Säve, P. sylvestris

(bark), 4.III.1973 Arvidsson (GB).

Suillosporium cystidiatum. Russia. Khabarovsk Reg.:

Solnechnyi Dist., Igdomi, Picea ajanensis, 5.VIII.2011

Spirin 3830*(H).

Acknowledgements Greet Van Autgaerden (Antwerpen, Belgium),

Eugeny Dunaev (Young Naturalist Club of the Zoological Museum,

Moscow University, Russia), and Alexander Ordynets (Kassel,

Germany) kindly provided us with valuable fungal collections. Serena

Lee organized and participated in field work in Singapore. Pirkko Harju

(Helsinki, Finland) identified host trees of some important specimens.

Author contribution All authors contributed to the study conception and

design. Material preparation, data collection, and analysis were initially

performed by Viacheslav Spirin, Sergey Volobuev, Ilya Viner, Otto

Miettinen, and Karl-Henrik Larsson. The authors Josef Vlasák, Nathan

Schoutteten, Viviana Motato-Vásquez, Heikki Kotiranta, and Hernawati

provided further important material and/or sequences. The first draft of

the manuscript was written by Viacheslav Spirin and all authors

commented on previous versions of the manuscript. All authors read

and approved the final manuscript.

Funding Open access funding provided by University of Helsinki includ-

ing Helsinki University Central Hospital. Komarov Botanical Institute

RAS (institutional research project “Biodiversity, ecology, structural

and functional features of fungi and fungus-like protists”,АААА-А19-

119020890079-6, with equipment of The CoreFacilities Center “Cell and

Molecular Technologies in Plant Science”) (St. Petersburg, Russia) (the

474 Mycol Progress (2021) 20:453–476

author SV); the grant of the President of the Russian Federation (project

MK-3216.2019.11) (the author SV); Societas pro Fauna et Flora Fennica

(the author IV); Academy of Sciences of the Czech Republic (project

number RVO: 60077344) (the author JV); Flemish Research Council

(FWO) (grant number 11E0420N) (the author NS); Coordenação de

Aperfeiçoamento Pessoal de Nível Superior –CAPES (Brazil) (the author

VMV); The Rufford Small Grants Foundation (the author VMV).

Data availability DNA sequences used in the present study are available

in GenBank. Alignments were deposited in TreeBASE. Fungal speci-

mens are stored in public herbaria (as indicated under “Specimens

examined”).

Declarations

Ethics approval Not applicable

Conflict of interest The authors declare no competing interests.

Open Access This article is licensed under a Creative Commons

Attribution 4.0 International License, which permits use, sharing, adap-

tation, distribution and reproduction in any medium or format, as long as

you give appropriate credit to the original author(s) and the source, pro-

vide a link to the Creative Commons licence, and indicate if changes were

made. The images or other third party material in this article are included

in the article's CreativeCommons licence, unless indicated otherwise in a

credit line to the material. If material is not included in the article's

Creative Commons licence and your intended use is not permitted by

statutory regulation or exceeds the permitted use, you will need to obtain

permission directly from the copyright holder. To view a copy of this

licence, visit http://creativecommons.org/licenses/by/4.0/.

References

Benson DA, Cavanaugh M, Clark K, Karsch-Mizrachi I, Ostell J, Pruitt

KD, Sayers EW (2018) GenBank. Nucleic Acids Res 46(D1):D41–

D47. https://doi.org/10.1093/nar/gkx1094

Boidin J, Gilles G (1990) Corticiés s.l. interessantes ou nouveax pour la

France (Basidiomycotina). Bull Soc Mycol France 106:135–167

Boidin J, Gilles G (1994) Contribution à la connaissance des Corticiés à

basides urniformes ou suburniformes (Basidiomycotina). Bull Soc

Mycol France 110:185–229

Eriksson J (1958) Studies in the Heterobasidiomycetes and

Homobasidiomycetes –Aphyllophorales of Muddus National Park

in North Sweden. Symb Bot Upsal 16:1–172

Eriksson J, Ryvarden L (1975) The Corticiaceae of North Europe. 3.

Fungiflora, Oslo

Eriksson J, Hjortstam K, Ryvarden L (1978) The Corticiaceae of North

Europe. 5. Fungiflora, Oslo

Eriksson J, Hjortstam K, Ryvarden L (1984) The Corticiaceae of North

Europe. 7. Fungiflora, Oslo

Gardes M, Bruns TD (1993) ITS primers with enhanced specificity for

basidiomycetes application to the identification of mycorrhizae and

rusts. Mol Ecol 2:132–118. https://doi.org/10.1111/j.1365-294x.

1993.tb00005.x

Gouy M, Guindon S, Gascuel O (2010) SeaView version 4: a

multiplatform graphical user interface for sequence alignment and

phylogenetic tree building. Mol Biol Evol 27(2):221–224. https://

doi.org/10.1093/molbev/msp259

Gruhn G, Alvarado P, Hallenberg N, Roy M, Courtecuisse R (2018)

Contribution to the taxonomy of Sistotremastrum (Trechisporales,

Basidiomycota) and the description of two new species,

S. fibrillosum and S. aculeocrepitans. Phytotaxa 379:27–38

Hallenberg N (1978) Wood-fungi (Corticiaceae, Coniophoraceae,

Lachnocladiaceae, Thelephoraceae) in North Iran. I. Iranian J Plant

Pat 14:38–87

Haynes KA, Westerneng TJ, Fell JW, Moens W (1995) Rapid detection

and identification of pathogenic fungi by polymerase chain reaction

amplification of large subunit ribosomal DNA. J Med Vet Mycol

33(5):319–325. https://doi.org/10.1080/02681219580000641

Huffman JA, Prenni AJ, DeMott PJ, Pöhlker C, Mason RH, Robinson

NH, Fröhlich-Nowoisky J, Tobo Y, Després VR, Garcia E, Gochis

DJ, Harris E, Müller-Germann I, Ruzene I, Schmer B, Sinha B, Day

DA, Andreae MO, Jimenez JL, Gallagher M, Kreidenweis SM,

Bertram AK, Pöschl U (2013) High concentration of biological

aerosol particles and ice nuclei during and after rain. Atmos Chem

Phys 13:6151–6164. https://doi.org/10.5194/acp-13-6151-2013

Jülich W (1982) Notes on some Basidiomycetes (Aphyllophorales and

Heterobasidiomycetes). Persoonia 11(4):421–428

Katoh K, Rozewicki J, Yamada KD (2017) MAFFT online service: mul-

tiple sequence align-ment, interactive sequence choice and visuali-

zation. Brief Bioinform: bbx108. https://doi.org/10.1093/bib/

bbx108

Kearse M, Moir R, Wilson A, Stones-Havas S, Cheung M, Sturrock S,

Buxton S, Cooper A, Markowitz S, Duran C, Thierer T, Ashton B,

Meintjes P, Drummond A (2012) Geneious Basic: an integrated and

extendable desktop software platform for the organization and anal-

ysis of sequence data. Bioinformatics 28(12):1647–1649. https://

doi.org/10.1093/bioinformatics/bts199

Larsson KH (1992) The genus Trechispora. University of Göteborg,

Göteborg

Larsson KH (2001) The position of Poria mucida inferred from nuclear

ribosomal DNA sequences. Harvard Papers Bot 6:131–138

Larsson KH (2007) Re-thinking the classification of corticioid fungi.

Mycol Res 111:1040–1063

Larsson KH, Larsson E, Kõljalg U (2004) High phylogenetic diversity

among corticioid homobasidiomycetes. Mycol Res 108:983–1002

Liu SL, Ma HX, He SH, Dai YC (2019) Four new corticioid species in

Trechisporales (Basidiomycota) from East Asia and notes on phy-

logeny of the order. MycoKeys 48:97–113

Menkis A, Allmer J, Vasiliauskas R, Lygis V, Stenlid J, Finlay R (2004)

Ecology and molecular characterization of dark septate fungi from

roots, living stems, coarse and fine woody debris. Mycol Res 108:

965–973

Miettinen O, Vlasák J, Rivoire B, Spirin V (2018) Postia caesia complex

(Polyporales, Basidiomycota) in temperate Northern Hemisphere.

Fungal Syst Evol 1:101–129

Milne I, Lindner D, Bayer M, Husmeier D, McGuire G, Marshall DF,

Wright F (2008) TOPALi v2: a rich graphical interface for evolu-

tionary analyses of multiple alignments on HPC clusters and multi-

core desktops. Bioinformatics 25(1):126–127. https://doi.org/10.

1093/bioinformatics/btn575

Nagy LG, Riley R, Tritt A, Adam C, Daum C, Floudas D, Sun H, Yadav

JS, Pangilinan J, Larsson K-H, Matsuura K, Barry K, Labutti K,

Kuo R, Ohm RA, Bhattacharya SS, Shirouzu T, Yoshinaga Y,

Martin FM, Grigoriev IV, Hibbett DS (2016) Comparative geno-

mics of early-diverging mushroom-forming fungi provides insights

into the origins of lignocellulose decay capabilities. Mol Biol Evol

33(4):959–970. https://doi.org/10.1093/molbev/msv337

Niemelä T (2016) Suomen käävät. Norrlinia 31:1–430

Niemelä T, Wallenius T, Kotiranta H (2002) The kelo tree, a vanishing

substrate of specified wood-inhabiting fungi. Polish Botanical

Journal 47:91–101

Nilsson RH, Larsson K-H,Taylor AFS, Bengtsson-Palme J, Jeppesen TS,

Schigel D, Kennedy P, Picard K, Glöckner FO, Tedersoo L, Saar I,

Kõljalg U, Abarenkov K (2018) The UNITE database for molecular

identification of fungi: handling dark taxa and parallel taxonomic

475Mycol Progress (2021) 20:453–476

classifications. Nucleic Acids Res 47(D1):D259–D264. https://doi.

org/10.1093/nar/gky1022

Oberwinkler F (1965) Primitive Basidiomyceten. Revision einiger

Formenkreise von Basidienpilzen mit plastischer Basidie. Sydowia

19:1–72

Ronquist F, Teslenko M, Van Der Mark P, Ayres DL, Darling A, Höhna

S, Larget B, Liu L, Suchard M, Huelsenbeck JP (2012) MrBayes

3.2: efficient Bayesian phylogenetic inference and model choice

across a large model space. Syst Biol 61:539–542. https://doi.org/

10.1093/sysbio/sys029

Stamatakis A (2006) Raxml-vi-hpc: maximum likelihood-based phylo-

genetic analyses with thousands of taxa and mixed models.

Bioinformatics 22:2688–2690. https://doi.org/10.1093/

bioinformatics/btl446

Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6:

molecular evolutionary genetics analysis version 6.0. Mol Biol Evol

30:2725–2729. https://doi.org/10.1093/molbev/mst197

Telleria MT, Melo I, Dueñas M, Salcedo I, Beltrán-Tejera E, Rodríguez-

Armas JL, Martín MP (2013a) Sistotremastrum guttuliferum: a new

species from the Macaronesian islands. Mycol Progress 12:687–692

Telleria MT, Melo I, Dueñas M, Larsson KH, Paz Martín MP (2013b)

Molecular analyses confirm Brevicellicium in Trechisporales. IMA

Fungus 4:21–28

Telleria MT, Dueñas M, Martín MP (2014) A new species of

Sistotremastrum (Basidiomycota, Trechisporales) from Huinay

Reserve. Phytotaxa 158:93–98

Thiers B (2019) Index Herbariorum: a global directory of public herbaria

and associated stuff [continuosly updated]. New York Botanical

Garden’s Virtual Herbarium. http://sweetgum.nybg.org/ih

Vilgalys R, Hester M (1990) Rapid genetic identification and mapping of

enzymatically amplified ribosomal DNA from several species of

Cryptococcus. J Bacteriol 172:4238–4246

Wu F, Yuan Y, Zhao CL (2015) Porpomyces submucidus

(Hydnodontaceae, Basidiomycota), a new species from tropical

China based on morphological and molecular evidence. Phytotaxa

230:61–68

Publisher’snote Springer Nature remains neutral with regard to jurisdic-

tional claims in published maps and institutional affiliations.

476 Mycol Progress (2021) 20:453–476

Outline, divergence times and phylogenetic analyses of Trechisporales (Agaricomycetes, Basidiomycota)

Article

Full-text available

Apr 2022

Phylogenetic analyses inferred from the nuc rDNA ITS1-5.8S-ITS2 (ITS) data set and the combined 2-locus data set [5.8S + nuc 28S rDNA (nLSU)] of taxa of Trechisporales around the world show that Sistotremastrum family forms a monophyletic lineage within Trechisporales. Bayesian evolutionary and divergence time analyses on two data sets of 5.8S and nLSU sequences indicate an ancient divergence of Sistotremastrum family from Hydnodontaceae during the Triassic period (224.25 Mya). Sistotremastrum family is characterized by resupinate and thin basidiomata, smooth, verruculose, or odontoid- semiporoid hymenophore, a monomitic hyphal structure, and generative hyphae bearing clamp connections, the presence of cystidia and hyphidia in some species, thin-walled, smooth, inamyloid, and acyanophilous basidiospores. In addition, four new species, namely, Trechispora dentata, Trechispora dimitiella, Trechispora fragilis, and Trechispora laevispora, are described and illustrated. In addition, three new combinations, namely, Brevicellicium daweishanense, Brevicellicium xanthum, and Sertulicium limonadense, are also proposed.

Outline, divergence times and phylogenetic analyses of Trechisporales (Agaricomycetes, Basidiomycota)

Article

Full-text available

Apr 2022

Zhan-Bo Liu

The genus Fomitopsis (Polyporales, Basidiomycota) reconsidered

Article

Full-text available

Feb 2024
STUD MYCOL

Based on seven-and three-gene datasets, we discuss four alternative approaches for a reclassification of Fomitopsidaceae (Polyporales, Basidiomycota). After taking into account morphological diversity in the family, we argue in favour of distinguishing three genera only, viz. Anthoporia, Antrodia and Fomitopsis. Fomitopsis becomes a large genus with 128 accepted species, containing almost all former Fomitopsis spp. and most species formerly placed in Antrodia, Daedalea and Laccocephalum. Genera Buglossoporus, Cartilosoma, Daedalea, Melanoporia, Neolentiporus, alongside twenty others, are treated as synonyms of Fomitopsis. This generic scheme allows for morphologically distinct genera in Fomitopsidaceae, unlike other schemes we considered. We provide arguments for retaining Fomitopsis and suppressing earlier (Daedalea, Caloporus) or simultaneously published generic names (Piptoporus) considered here as its synonyms. Taxonomy of nine species complexes in the genus is revised based on ITS, ITS + TEF1, ITS + TEF1 + RPB1 and ITS + TEF1 + RPB2 datasets. In total, 17 species are described as new to science, 26 older species are reinstated and 26 currently accepted species names are relegated to synonymy. A condensed identification key for all accepted species in the genus is provided.

Xenasmatellales ord. nov. and Xenasmatellaceae fam. nov. for Xenasmatella ( Agaricomycetes, Basidiomycota )

Article

Full-text available

Jun 2023

In the era of molecular phylogeny as dominant evidence in fungal taxonomy, the taxonomic framework of fungi adopted from morphological characteristics has been largely updated. Compared with other fungal groups, macrofungi underwent fewer updates at the order and higher level. In this study, the taxonomic placement of a poorly known macro-basidiomycetous genus Xenasmatella is studied. Phylogenetic and molecular clock analyses inferred from a seven-locus dataset support that the genus represents an order rank lineage. Accordingly, a monotypic order Xenasmatellales and a monotypic family Xenasmatellaceae are newly introduced for Xenasmatella within Agaricomycetes. The species diversity and relationships of Xenasmatella are further clarified with the aid of the phylogenetic analysis inferred from a four-locus dataset. In association with morphological characteristics, a new species Xenasmatella hjortstamii is described. Moreover, the distribution of Xenasmatella ailaoshanensis, X. gossypina, and X. wuliangshanensis previously known only from type localities in Yunnan Province, China are expanded. In addition, two unnamed single-specimen lineages of Xenasmatella from Victoria State, Australia and Sichuan, China are revealed, likely representing two potential new species of this genus. In summary, the current study updates the taxonomic framework of Agaricomycetes and provides a crucial supplement for comprehensively understanding the evolutionary history of this fungal class.

IDENTIFICAÇÃO DE MACROFUNGOS DA TRILHA DO TUCUM - FRAGMENTO DE MATA ATLÂNTICA DO EXTREMO SUL DA BAHIA

Research

Full-text available

Dec 2023

Este trabalho teve como objetivo identificar diversos tipos de macrofungos coletados na trilha do Tucun, fragmento de Mata Atlântica do Extremo Sul da Bahia. As coletas foram realizadas na Trilha do Tucum (17º34’S e 39º43’O) localizado dentro do Campus do Instituto Federal Baiano (IFBaiano) de Teixeira de Freitas-BA. Foram realizadas no período de abril de 2022 a março de 2023, totalizando quatro coletas durante esse período. Utilizou-se a técnica da amostragem oportunista, onde eram procurados e coletados os macrofungos em diferentes substratos (solo, troncos, galhos, folhas, serapilheira, etc.) na trilha e próximos (margem) à trilha, de acordo com a acessibilidade para a coleta dos espécimes. Todo material foi transportado para o Laboratório de Biologia dos Fungos do Campus X da Universidade do Estado da Bahia (UNEB) para processamento das amostras e análise. Foram coletados 157 espécimes de macrofungos, desse total foram identificados dois grandes grupos, sendo eles pertencentes aos filos Basidiomycota e Ascomycota. 56 (35,67%) foram identificados em nível de gênero ou espécie, 9 (5,74%) foram identificadas como possíveis espécies para a confirmação e 92 (58,56%) ainda não foram identificados. Dos 56 identificados em nível de espécie ou gênero, 53 (94,65%) pertencem ao filo Basidiomycota e três (5,35%) ao filo Ascomycota. Com base nas análises realizadas ao longo da pesquisa, verificou-se que na Trilha do Tucum, o filo de macrofungos mais prevalente é o Basidiomycota, apresentando o maior número de espécies identificadas. Com destaque para a classe Agaricomycetes, ordens Polyporales e Agaricales e família Polyporaceae.

Ergänzungen zur Funga der Steiermark 4

Article

Full-text available

Apr 2023

Outline of Fungi and fungus-like taxa – 2021

Article

Feb 2022

Trechisporales emended with a segregation of Sistotremastrales ord. nov. (Basidiomycota)

Article

Full-text available

Nov 2022

Trechisporales, typified by Trechispora and equivalent to Hydnodontales, is a recently introduced order within Agaricomycetes. This order only comprises one family Hydnodontaceae and 16 independent genera, but the relationships among these genera are not fully clarified. Here, via a wider sampling especially from Asia Pacific, careful morphological examinations and comprehensive multilocus-based phylogenetic analyses, the classification of Trechisporales is emended. Sertulicium and Sistotremastrum are segregated from Trechisporales, and placed in the new family Sistotremastraceae within the new order Sistotremastrales. A new genus Allotrechispora segregated from Trechispora is introduced within Hydnodontaceae, Trechisporales, and Boidinella, Litschauerella and Sphaerobasidium are excluded from Trechisporales. Brief summaries to genera accepted in Sistotremastrales and Trechisporales, and a key to all 12 genera accepted in Trechisporales are provided. In addition, Tomentella and Murrilloporus, potential synonyms of Trechispora, are excluded from Trechisporales and of uncertain position, respectively. At the species level, 19 new species are described with one from Allotrechispora, one from Fibrodontia, one from Subulicystidium and 16 from Trechispora, and seven new combinations are proposed with two for Allotrechispora and five for Trechispora. In addition, Trechispora yunnanensis is excluded from Trechispora. A key to all 87 species accepted in Trechispora is provided. In conclusion, an emended classification of Trechisporales within Agaricomycetes is constructed, which will help to further clarify species diversity and explore trait evolution within Trechisporales.

A Molecular Systematics and Taxonomy Research on Trechispora (Hydnodontaceae, Trechisporales): Concentrating on Three New Trechispora Species from East Asia

Article

Full-text available

Sep 2022
J. Fungi

Trechispora are an important genus of wood-inhabiting fungi that have the ability to decompose rotten wood in the forest ecosystem. In this study, we reported three new species of Trechispora: T. murina, T. odontioidea, T. olivacea from a subtropical region of Yunnan Province, China. Species descriptions were based on a combination of morphological features and phylogenetic analyses of the ITS and LSU region of nuclear ribosomal DNA. Trechispora murina is characterized by the resupinate basidiomata, grandinioid hymenial surface with a greyish tint, monomitic hyphal system and ellipsoid, thick-walled, ornamented basidiospores; T. odontioidea has an odontioid hymenial surface with cylindrical to conical, blunt aculei and subglobose to globose, colorless, slightly thick-walled, ornamented basidiospores; T. olivacea has a farinaceous hymenial surface with olivaceous tint, basidia clavate and thick-walled, ornamented, broadly ellipsoid to globose basidiospores. Sequences of the ITS and nLSU rDNA markers of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony, and Bayesian inference methods. After a series of phylogenetic analyses, the 5.8S+nLSU dataset was constructed to test the phylogenetic relationship of Trechispora with other genera of Hydnodontaceae. The ITS dataset was used to evaluate the phylogenetic relationship of the three new species with other species of Trechispora. Using ITS phylogeny, the new species T. murina was retrieved as a sister to T. bambusicola with moderate supports; T. odontioidea formed a single lineage and then grouped with T. fimbriata and T. nivea; while T. olivacea formed a monophyletic lineage with T. farinacea, T. hondurensis, and T. mollis.

Outline of Fungi and fungus-like taxa – 2021

Article

Full-text available

Aug 2022

Madhara K. Wimalasena

This paper provides an updated classification of the Kingdom Fungi (including fossil fungi) and fungus-like taxa. Five-hundred and twenty-three (535) notes are provided for newly introduced taxa and for changes that have been made since the previous outline. In the discussion, the latest taxonomic changes in Basidiomycota are provided and the classification of Mycosphaerellales are broadly discussed. Genera listed in Mycosphaerellaceae have been confirmed by DNA sequence analyses, while doubtful genera (DNA sequences being unavailable but traditionally accommodated in Mycosphaerellaceae) are listed in the discussion. Problematic genera in Glomeromycota are also discussed based on phylogenetic results.

Four new corticioid species in Trechisporales (Basidiomycota) from East Asia and notes on phylogeny of the order

Article

Full-text available

Mar 2019

Four new species in Trechisporales from East Asia, Dextrinocystiscalamicola , Subulicystidiumacerosum , S.tropicum and Tubuliciumbambusicola , are described and illustrated, based on morphological and molecular evidence. The phylogeny of Trechisporales was inferred from a combined dataset of ITS-nrLSU sequences. In the phylogenetic tree, Sistotremastrum formed a family-level clade of its own, sister to the Hydnodontaceae clade formed by all other genera. Dextrinocystis , is for the first time, confirmed as a member of Hydnodontaceae. A key to all the accepted genera in Trechisporales is given.

The UNITE database for molecular identification of fungi: handling dark taxa and parallel taxonomic classifications

Article

Full-text available

Jan 2019
NUCLEIC ACIDS RES

UNITE (https://unite.ut.ee/) is a web-based database and sequence management environment for the molecular identification of fungi. It targets the formal fungal barcode-the nuclear ribosomal internal transcribed spacer (ITS) region-and offers all ∼1 000 000 public fungal ITS sequences for reference. These are clustered into ∼459 000 species hypotheses and assigned digital object identifiers (DOIs) to promote unambiguous reference across studies. In-house and web-based third-party sequence curation and annotation have resulted in more than 275 000 improvements to the data over the past 15 years. UNITE serves as a data provider for a range of metabarcoding software pipelines and regularly exchanges data with all major fungal sequence databases and other community resources. Recent improvements include redesigned handling of unclassifiable species hypotheses, integration with the taxonomic backbone of the Global Biodiversity Information Facility, and support for an unlimited number of parallel taxonomic classification systems.

Postia caesia complex (Polyporales, Basidiomycota) in temperate Northern Hemisphere

Article

Full-text available

Mar 2018

Taxonomy of the Postia caesia complex is revised based on morphology and two genetic markers, ITS and tef1. In total, we recognize 24 species, multiplying the known species diversity in the complex. We provide descriptions for 20 temperate Northern Hemisphere taxa. Identity of the core species, P. caesia, is re-established, and a neotype from the type locality is selected. Four new combinations are proposed, and 10 new species are described: P. arbuti, P. auricoma, P. bifaria, P. comata, P. cyanescens, P. glauca, P. livens, P. magna, P. populi, and P. yanae.

MAFFT online service: Multiple sequence alignment, interactive sequence choice and visualization

Article

Full-text available

Sep 2017
BRIEF BIOINFORM

This article describes several features in the MAFFT online service for multiple sequence alignment (MSA). As a result of recent advances in sequencing technologies, huge numbers of biological sequences are available and the need for MSAs with large numbers of sequences is increasing. To extract biologically relevant information from such data, sophistication of algorithms is necessary but not sufficient. Intuitive and interactive tools for experimental biologists to semiautomatically handle large data are becoming important. We are working on development of MAFFT toward these two directions. Here, we explain (i) the Web interface for recently developed options for large data and (ii) interactive usage to refine sequence data sets and MSAs.

Comparative Genomics of Early-Diverging Mushroom-Forming Fungi Provides Insights into the Origins of Lignocellulose Decay Capabilities

Article

Full-text available

Dec 2015

Evolution of lignocellulose decomposition was one of the most ecologically important innovations in fungi. White rot fungi in the Agaricomycetes (mushrooms and relatives) are the most effective microorganisms in degrading both cellulose and lignin components of woody plant cell walls (PCW). However, the precise evolutionary origins of lignocellulose decomposition are poorly understood, largely because certain early-diverging clades of Agaricomycetes and its sister group, the Dacrymycetes, have yet to be sampled, or have been undersampled, in comparative genomic studies. Here, we present new genome sequences of 10 saprotrophic fungi, including members of the Dacrymycetes and early-diverging clades of Agaricomycetes (Cantharellales, Sebacinales, Auriculariales, and Trechisporales), which we use to refine the origins and evolutionary history of the enzymatic toolkit of lignocellulose decomposition. We reconstructed the origin of ligninolytic enzymes, focusing on class II peroxidases (AA2), as well as enzymes that attack crystalline cellulose. Despite previous reports of white rot appearing as early as the Dacrymycetes, our results suggest that white rot fungi evolved later in the Agaricomycetes, with the first class II peroxidases reconstructed in the ancestor of the Auriculariales and residual Agaricomycetes. The exemplars of the most ancient clades of Agaricomycetes that we sampled all lack class II peroxidases, and are thus concluded to use a combination of plesiomorphic and derived PCW degrading enzymes that predate the evolution of white rot.

Sistotremastrum chilensis (Trechisporales, Basidiomycota), a new species from Chilean Patagonia

Article

Full-text available

Jan 2014

Sistotrematrum chilensis sp. nov. is described and illustrated on the basis of morphological and molecular data. Specimens of this corticioid fungus were collected in Huinay Reserve, in the Valdivian temperate rainforest of the Chilean Northern Patagonian region. Affinities with other species of the genus are discussed.

Contribution to the taxonomy of Sistotremastrum (Trechisporales, Basidiomycota) and the description of two new species, S. fibrillosum and S. aculeocrepitans

Article

Nov 2018

Two new species of Sistotremastrum collected in French West Indies and French Guyana are described and illustrated. Morphological studies and molecular sequence data from two ribosomal DNA regions (ITS and 28S rDNA) support the recognition of S. fibrillosum and S. aculeocrepitans, two species characterized by their hyphal cords and basidia with 4 sterigmata.

GenBank

Article

Nov 2017
NUCLEIC ACIDS RES

GenBank® (www.ncbi.nlm.nih.gov/genbank/) is a comprehensive database that contains publicly available nucleotide sequences for 400 000 formally described species. These sequences are obtained primarily through submissions from individual laboratories and batch submissions from large-scale sequencing projects, including whole genome shotgun and environmental sampling projects. Most submissions are made using BankIt, the National Center for Biotechnology Information (NCBI) Submission Portal, or the tool tbl2asn. GenBank staff assign accession numbers upon data receipt. Daily data exchange with the European Nucleotide Archive and the DNA Data Bank of Japan ensures worldwide coverage. GenBank is accessible through the NCBI Nucleotide database, which links to related information such as taxonomy, genomes, protein sequences and structures, and biomedical journal literature in PubMed. BLAST provides sequence similarity searches of GenBank and other sequence databases. Complete bimonthly releases and daily updates of the GenBank database are available by FTP. Recent updates include changes to sequence identifiers, submission wizards for 16S and Influenza sequences, and an Identical Protein Groups resource.

The position of Poria mucida inferred from nuclear ribosomal DNA sequences

Article

Jan 2001

Karl-Henrik Larsson

Corticiés s.l. intéressants ou nouveaux pour la France (Basidiomycotina)

Article

Jan 1990

On Sistotremastrum and similar-looking taxa (Trechisporales, Basidiomycota)

Abstract and Figures

Recommended publications

Hendrich, L., Hawlitschek, O. & Balke, M. (2009): The epigean Australasian species of Neobidessodes...

Four new corticioid species in Trechisporales (Basidiomycota) from East Asia and notes on phylogeny...

Additions to the taxonomy of Lagarobasidium and Xylodon (Hymenochaetales, Basidiomycota)

On Craterocolla and Ditangium (Sebacinales, Basidiomycota)

Sistotremastrum limonadense sp. nov. from French Guiana