Phylogenetic analyses
Thirty-four sequences (14 ITS, 10 nLSU, and 10 RPB2) from fourteen specimens were produced and submitted to GenBank. The final combined dataset comprised 90 samples representing 44 taxa (Table 1) and 2992 nucleotide sites, with 895 bp ITS, 1402 bp LSU, and 659 bp RPB2. Subsequently, the best model, GTR + I + G (lset nst = 6, rates = invgamma; prset statefreqpr = Dirichlet (1,1,1,1)), was selected for each of the three datasets. Phylogenetic trees inferred from the ML and BI analyses were nearly identical but with a few statistical differences. As a result, an optimal scoring tree was provided using the ML with combined support data.
Table 1
Information on taxa used in the phylogenetic analysis.
Taxa
|
Voucher
|
Genbank accession number
|
Country
|
Reference
|
|
|
ITS
|
LSU
|
RPB2
|
|
|
Inocybe lanuginosa
|
PBM956
|
HQ232480
|
KP170923
|
KM245992
|
Washington
|
Matheny et al. (2020)
|
Inocybe relicina
|
JV10258
|
AF325664
|
AY038324
|
AY333778
|
Finland
|
Matheny et al. (2020)
|
Mallocybe. africana
|
BRF4123
|
|
MK908842
|
|
Benin
|
Unpublished
|
M. africana
|
HLA0462
|
MT458691
|
MT456364
|
|
Benin
|
Aignon et al. (2021)
|
M. africana
|
MR00358
|
MT476160
|
MT509360
|
MT628398
|
Benin
|
Aignon et al. (2021)
|
M. africana
|
MR00369
|
MT476162
|
MT509361
|
|
Burkina Faso
|
Aignon et al. (2021)
|
M. africana
|
MR00385
|
MN096194
|
MN097886
|
MT465593
|
Togo
|
Aignon et al. (2021)
|
M. africana
|
PC:0088767
|
MN178510
|
MN178542
|
|
Zambia
|
Unpublished
|
M. agardhii
|
AB980912
|
HM209790
|
HM209790
|
|
Denmark
|
Larsson and Vauras (2012)
|
M. arenaria
|
EL25008
|
FN550937
|
FN550937
|
|
France
|
Ryberg M et al. (2010)
|
M. aurantiodisca
|
2020ZD01
|
OM179937
|
|
|
China
|
The present study
|
M. aurantiodisca
|
NJ3109
|
OM179935
|
OM138834
|
OM835751
|
China
|
The present study
|
M. aurantiodisca
|
NJ3396
|
OM179936
|
OM138835
|
OM835752
|
China
|
The present study
|
M. arthrocystis
|
EL9207
|
FN550941
|
FN550941
|
|
Sweden
|
Ryberg et al. (2010)
|
M. caesariata
|
NAMA272
|
EU819498
|
|
|
USA
|
Palmer et al. (2008)
|
M. caesariata
|
JMP0105
|
EU819473
|
|
|
USA
|
Palmer et al. (2008)
|
M. cf. dulcamara
|
CLC1333
|
GU980635
|
GU980635
|
|
USA
|
Cripps et al. (2010)
|
M. cf. squarrosoannulata
|
CLC1844
|
GU980611
|
GU980611
|
|
USA
|
Cripps et al. (2010)
|
M. cf. subtilior
|
PERTH:08383081
|
KP641629
|
KP171084
|
KM656125
|
Australia
|
Matheny and Bougher (2014)
|
M. depressa
|
BJTC FM1300
|
OM801895
|
OM801900
|
OM780099
|
China
|
Mao et al. (2022)
|
M. dulcamara
|
EL59-05
|
GU980643
|
GU980643
|
|
Norway
|
Cripps et al. (2010)
|
M. errata
|
DED8022
|
|
EU569844
|
|
Thailand
|
Matheny et al. 2009
|
M. fibrillosa
|
LVK14371
|
MN178498
|
MN178526
|
MN203517
|
USA
|
Unpublished
|
M. fibrillosa
|
LVK14390
|
MN178499
|
MN178527
|
MN203518
|
USA
|
Unpublished
|
M. fulviceps
|
PBM4542
|
MZ404929
|
MZ375431
|
|
USA
|
Unpublished
|
M. fulvipes
|
EL3705
|
AM882858
|
|
|
Norway
|
Ryberg et al (2008)
|
M. fulvipes
|
EL8307
|
FN550935
|
FN550935
|
|
Sweden
|
Unpublished
|
M. fulvipes
|
EL99-07
|
GU980600
|
GU980600
|
|
Sweden
|
Cripps et al. (2010)
|
M. fulvoumbonata
|
PBM4537
|
MZ404931
|
MZ375433
|
|
USA
|
Unpublished
|
M. fuscomarginata
|
BJ890718
|
GU980656
|
GU980656
|
|
Sweden
|
Cripps et al. (2010)
|
M. fuscomarginata
|
EL10906
|
FN550940
|
FN550940
|
|
Sweden
|
Ryberg et al. (2010)
|
M. granulosa
|
EL138-09
|
KR029727
|
KR029727
|
|
Sweden
|
Ariyawansa et al. (2015)
|
M. granulosa
|
SJ84030
|
KR029725
|
KR029725
|
|
Sweden
|
Ariyawansa et al. (2015)
|
M. gymnocarpa
|
16413
|
JF908161
|
|
|
Italy
|
Osmundson et al.(2013)
|
M. gymnocarpa
|
SJ980707
|
AM882866
|
AM882866
|
|
Sweden
|
Ryberg et al. (2008)
|
M. isabellina
|
PERTH:07699255
|
KP171137
|
KP170915
|
KJ811581
|
Australia
|
Unpublished
|
M. isabellina
|
PERTH:08096635
|
KP171138
|
KP170916
|
KJ811582
|
Australia
|
Unpublished
|
M. latispora
|
EL190-08
|
KR029724
|
KR029724
|
|
Not given
|
Ariyawansa et al. (2015)
|
M. latispora
|
JV19640F
|
MN178503
|
MN178529
|
MN203520
|
Finland
|
Matheny et al. (2019)
|
M. leucoblema
|
JV2898
|
HM209789
|
HM209789
|
|
Finland
|
Larsson and Vauras (2012)
|
M. leucoloma
|
Kuhner63-36Type
|
GU980614
|
|
|
Geneva
|
Cripps et al. (2010)
|
M. leucoblema
|
SM2324
|
GU980630
|
GU980630
|
|
Sweden
|
Cripps et al. (2010)
|
M. leucoloma
|
EL41-07
|
GU980622
|
GU980622
|
|
Sweden
|
Cripps et al. (2010)
|
M. leucoloma
|
Ohenoja 880810
|
HM209786
|
HM209786
|
|
Svalbard
|
Larsson and Vauras (2012)
|
M. longicystis
|
FYG2015407
|
OM179933
|
|
|
China
|
The present study
|
M.longicystis
|
FYG6371
|
OM179926
|
OM135609
|
OM835746
|
China
|
The present study
|
M. longicystis
|
FYG6373
|
OM179927
|
OM135610
|
OM747850
|
China
|
The present study
|
M. longicystis
|
FYG6374
|
OM179928
|
OM135611
|
OM835747
|
China
|
The present study
|
M. longicystis
|
FYG6376
|
OM179929
|
OM135612
|
OM835745
|
China
|
The present study
|
M. longicystis
|
FYG6378
|
OM179930
|
OM135613
|
OM835748
|
China
|
The present study
|
M. longicystis
|
FYG6501
|
OM179934
|
|
|
China
|
The present study
|
M. longicystis
|
FYG6880
|
OM179931
|
OM135614
|
OM858853
|
China
|
The present study
|
M. longicystis
|
HT370
|
OM179932
|
OM135615
|
|
China
|
The present study
|
M. malenconii
|
JV23101
|
HM209787
|
HM209787
|
|
Finland
|
Larsson and Vauras (2012)
|
M. malenconii
|
PAM98941302
|
HM209788
|
HM209788
|
|
France
|
Larsson and Vauras (2012)
|
M. multispora
|
CO4248
|
MN178509
|
MN178540
|
|
USA
|
Matheny and Kudzma (2019)
|
M. myriadophylla
|
EL121-08
|
HM209792
|
HM209792
|
|
Sweden
|
Larsson and Vauras (2012)
|
M. myriadophylla
|
JV5968
|
HM209794
|
HM209794
|
|
Finland
|
Larsson and Vauras (2012)
|
M. myriadophylla
|
JV19652
|
HM209791
|
HM209791
|
|
Finland
|
Larsson and Vauras (2012)
|
M. myriadophylla
|
JV19678
|
HM209793
|
HM209793
|
|
Finland
|
Larsson and Vauras (2012)
|
M. pallidipes
|
FYG3726
|
OM179924
|
OM137052
|
OM835749
|
China
|
The present study
|
M. pallidipes
|
FYG3727
|
OM179925
|
|
OM835750
|
China
|
The present study
|
M. picea
|
BJTC FM555
|
OM801896
|
OM801901
|
OM780096
|
China
|
Mao et al. (2022)
|
M. picea
|
BJTC FM569
|
OM801897
|
OM801903
|
OM780097
|
China
|
Mao et al. (2022)
|
M. pygmaea
|
EL48-05
|
GU980628
|
GU980628
|
|
Norway
|
Cripps et al. (2010)
|
M. pygmaea
|
J. Favre76bisType
|
GU980629
|
|
|
Norway
|
Cripps et al. (2010)
|
M. pyrrhopoda
|
TENN:066987
|
KP308813
|
KP170983
|
KM406223
|
Australia
|
Matheny and Bougher (2017)
|
M. pyrrhopoda
|
PERTH:08383278
|
KP308814
|
KP170984
|
KM406224
|
Australia
|
Matheny and Bougher (2017)
|
M. pyrrhopoda
|
PERTH:08557764
|
KP308815
|
KP170986
|
KM406226
|
Australia
|
Matheny and Bougher (2017)
|
M. sabulosa
|
PERTH:07680732
|
KP308822
|
JN974916
|
KM406235
|
Australia
|
Horak et al. (2015)
|
M. sabulosa
|
PERTH:08320322
|
KP308821
|
KP170994
|
KM406234
|
Australia
|
Unpublished
|
M. siciliana
|
AMB 18274
|
MG757417
|
MG757419
|
|
Italy
|
Unpublished
|
M. siciliana
|
M73
|
MW354997
|
|
|
Hungary
|
Consiglio et al. (2020)
|
M. squarrosoannulata
|
K63-236Type
|
HM209795
|
|
|
Geneva
|
Larsson and Vauras (2012)
|
M. subdecurrens
|
REH10168
|
MH024850
|
MH024886
|
MH577503
|
USA
|
Matheny et al. (2020)
|
M. subflavospora
|
NLB1078
|
MN178515
|
MN178544
|
MH577504
|
Australia
|
Unpublished
|
M. subflavospora
|
TENN:067023
|
KP641620
|
|
KM656119
|
Australia
|
Horak et al. (2015)
|
M. substraminipes
|
EL12-08
|
GU980607
|
GU980607
|
|
USA
|
Cripps et al. (2010)
|
M. substraminipes
|
K70-148
|
GU980601
|
GU980601
|
|
USA
|
Cripps et al. (2010)
|
M. subtilior
|
PERTH:08095388
|
KP641628
|
KP171082
|
|
Australia
|
Mathenyand Bougher (2017)
|
M. squamosodisca
|
LVK20133
|
MZ404935
|
MZ375436
|
|
USA
|
Unpublished
|
M. subtomentosa
|
LVK17005
|
MN178520
|
|
|
USA
|
Unpublished
|
M. subtomentosa
|
PBM2460
|
MN178521
|
MN178549
|
MN203531
|
USA
|
Unpublished
|
M. terrigena
|
EL24-08
|
GU980648
|
|
|
USA
|
Cripps et al. (2010)
|
M. tomentosula
|
PBM4138
|
MG773814
|
MK421969
|
MH577506
|
USA
|
Matheny et al. (2020)
|
M. umbrinofusca
|
Kuhner70-38Type
|
GU980613
|
|
|
Geneva
|
Cripps et al. (2010)
|
M. unicolor
|
PBM2589
|
EU523555
|
|
|
USA
|
Unpublished
|
M. unicolor
|
PBM2974
|
MN178524
|
JQ313569
|
MN203532
|
USA
|
Unpublished
|
M. velutina
|
MSM # 0048
|
MK990129
|
MK999927
|
|
Pakistan
|
Saba and Khalid (2020)
|
M. velutina
|
MSM # 0049
|
MK990130
|
MK999928
|
|
Pakistan
|
Saba and Khalid (2020)
|
M. velutina
|
MSM # 0050
|
MK990131
|
MK999929
|
|
Pakistan
|
Saba and Khalid (2020)
|
M. terrigena
|
EL11704
|
AM882864
|
AM882864
|
|
Sweden
|
Ryberg et al. (2008)
|
In Fig. 1, all members of Mallocybe are grouped and divided into four major clades, namely, clades A–D. Fifty-three samples grouped into clade A had a strong support (PP = 1/BP = 94). Of these samples in clade A, while 33 formed a subclade with another strong support (PP = 1/BP = 97), six samples each from M. arenaria (Kühner) Matheny & Esteve-Rav., M. velutina Saba & Khalid, and M. tomentosula Matheny & Esteve-Rav., clustered in a fully supported subclade separated from the others, whereas seven samples from M. terrigena (Fr.) Matheny, Vizzini & Esteve-Rav., and M. fibrillosa (Peck) Matheny & Esteve-Rav., clustered together, although with a moderate support (PP = 0.85 / BP = 72). Additionally, seven samples from M. piceae, M. arthrocystis (Kühner) Matheny & Esteve-Rav., M. fuscomarginata (Kühner) Matheny & Esteve-Rav., and M. gymnocarpa (Kühner) Matheny & Esteve-Rav., were also grouped in a strongly supported (PP = 0.95 / BP = 97) subclade. Contrastively, 11 samples from Australia were grouped in clade B with a full support. Therefore, clades A and B were grouped together with a strong support (PP = 0.99/ BP = 99). Similarly, while 20 samples were grouped into clade C with a full support where our three new species nested, six samples from Old World tropical regions clustered together in a full support clade, namely, clade D.
The Chinese materials formed three independent lineages and were all placed in clade C. Therefore, we labeled the clade the “longicystis clade.” in this study. Seven samples from Hainan Province and one from Yunnan Province also formed a full support lineage, representing M. longicystis. Thus, we propose that this lineage is sister to that of M. aurantiodisca with three samples from Zhejiang Province. Additionally, two samples of M. pallidipes collected from the Jilin Province formed a full support lineage. Hence, they were also proposed as sisters to the subclade, unifying M. aurantiodisca, M. longicystis, M. multispora (Murrill) Matheny & Esteve-Rav., and M. unicolor (Peck) Matheny & Esteve-Rav.
Taxonomy
Mallocybe longicystis T. Bau, Y.G. Fan, J.H. Hu & W.J. Yu, sp. nov., Figs. 2–3
MycoBank: MB844269
Etymology
longicystis (Latin) refers to its cylindrical cheilocystidia.
Diagnosis
differs from M. pallidipes by the lack of reddish orange tinge in basidiomata, its erected scales in pileus, and more cylindrical cheilocystidia.
Holotype: China, Hainan province, Shuiman Township, Wuzhishan City, Wuzhishan area of Hainan Tropical Rain Forest National Park, 18°51ʹ53ʹʹN, 109°40ʹ43ʹʹE, 695 m asl., 28 Jul. 2021, Y.-G. Fan & W.-J. Yu, FYG6374 (FCAS3535), GenBank accession number: ITS (OM179928), LSU (OM135611), and RPB2 (OM835747).
Description
Basidiomata small-sized. Pileus 16–30 mm diam. spherical to hemispherical when very young, becoming convex to broadly convex and nearly flattened when mature, sometimes turns up in a wavy shape, without umbo; margin incurved at first, then decurved for a long time, straight when mature, longer than lamellae; surface dry, covered with densely and radially arranged, thick, conical scales, erected towards center, becoming recurved outwards, nearly appressed to appressed-rimulose towards the margin; amber, burnt yellowish (4B6) to yellowish brown (5C7) at the center, darker towards the disc and slightly paler outwards; occasionally with a thin smoky-yellowish (5B6) filamentous veil remnants layer around the disc, sometimes not distinctly. Lamellae 2–4 mm wide, adnexed, crowded, subdecurrent, alternating with 3–4 tiers of lamellula, whitish (3A1) to grayish white (3B1) or dirty white (3B2) when young, beige (5B2), yellowish (5B4) to brownish (5C4) when mature, edges paler and fimbriate. Stipe 19–40 × 2–5 mm, solid at first, becoming fistulose with age, equal, truncate or pestle like and slightly swollen at the base; woolly or feltly from veil remnants, grayish white (3B2) to yellowish white (4C4) when young, yellowish brown (5B5) when mature; partial veil present when young, fugacious. Context solid and fleshy in pileus, white (5A1) to dirty whitish (4B2), 1‒2 mm thick at middle radius, 2‒3 mm thick at the center, fleshy to somewhat fibrous in the stipe, whitish (5A2) to yellow whitish(3B2), with light yellowish brown (5B4) tinge near the epidermis. Odor lightly sweety, lightly earthy or not distinct.
Basidiospores: [160/8/8] (8.2)8.8–9.7–10.2(10.8) × (3.9)4.3–5.1–5.6(8.2) µm, Q = (1.52)1.59–2.20(2.64), Qm ± SD = 1.92 ± 0.015, ellipsoid to oblong, smooth, thick-walled, with blunt or slightly acute apex, golden yellowish to pale yellowish in KOH, apiculus small and indistinct, with one large ellipsoid oily droplet. Basidia 24–34 × 5–9 µm, slenderly clavate to clavate, blunt or rounded at apex, nearly truncate or pestle-like at the base, colorless at the initial stage, then golden yellowish and shriveled, 4- or 2-spored; necropigmented, sterigmata acute, 3–6 µm in length. Pleurocystidia absent. Lamellae edge sterile. Cheilocystidia 35–63 × 5–14 µm (n = 50), abundant, in clusters, slenderly clavate or cylindrical-clavate, less often broadly clavate or ventricose, mostly enlarged and rounded at apex, occasionally utriform or ventricose, thin-walled or slightly thick-walled, walls bright yellow. Hymenophoral trama 65–150 µm thick, regular to subregular, yellowish to golden yellowish; trama hyphae 10–30 µm wide, smooth, concave, inflated at both ends of cell, cylindrical, thin-walled or slightly thick-walled, walls bright yellow. Stipitipellis a cutis often extended with irregularly and loosely arranged hyphae, golden yellowish in mass, composed of cylindrical inflated cells, 7–15 µm wide, smooth, colorless to light yellowish. Stipe trama regularly arranged, light yellowish when aggregated, composed of smooth, cylindrical hyphae, colorless, 5–10 µm wide. Caulocystidia not observed. Pileipellis a cutis with emerged bundles of trichodermally arranged hyphae comprising scales, those bundles 93–140 µm wide, coniform, golden yellowish to yellowish brown when aggregated, composed of cylindrical to inflated encrusted, hyphae 7–18 µm wide, slightly thickened, bright yellow. Pileal trama 250–650 µm wide, subregular, yellowish in mass, composed of fleshy, cylindrical hyphae, colorless, 11–20 µm wide. Oleiferous hyphae 3–5 µm in length of two types: yellowish type often present in pileal trama, with oily inclusions, colorless type more often observed in stipe trama, smooth, with no oily inclusions. Clamp connections present in all tissues.
Habitat
gregarious, caespitose in small groups or scattered along roadsides under fagaceous trees, on sandy or lateritic soil.
Distribution
Known from Hainan and Yunnan Provinces, China.
Specimens examined
China. Hainan Province, Wuzhishan City, Shuiman Town, 18°51ʹ53ʹʹN, 109°40ʹ43ʹʹE, 695 m asl., under fagaceous trees, 26 May 2022, Y.-G. Fan & W.-J. Yu, FYG6972 (FCAS3583), 1 May 2022, Y.-G. Fan & W.-J. Yu, FYG6963 (FCAS3581), FYG6964 (FCAS3582); same locality, 28 Jul. 2021, Y.-G. Fan & J.-H. Hu, FYG6371 (FCAS3533), FYG6373 (FCAS3534), FYG6376 (FCAS3536), Y.-G. Fan, L.-S. Deng, L.-N. Zhao & J.-H. Hu, FYG6378 (FCAS3537), Y.-G. Fan & W.-J. Yu, FYG6880 (FCAS3538), Y.-G. Fan & W.-J. Yu, same locality, 30 Jun 2021, T. Bau & Y.-G. Fan, FYG6501 (FCAS3541), same locality, 02 Aug 2020, MHKMU T. Huang 370 (FCAS3539); Yunnan Province, Kunming City, Kunming Botanic Garden, 25 Sep 2015, Y.-G. Fan & W.-J. Yu, FYG2015407 (FCAS3540).
Remarks
This species fruits from late April to late September under fagaceous forests in tropical or subtropical China. The umber-colored basidiomata and erected squamules in pileus make it outstanding in the field. The pileus surface also exhibits nearly appressed scales in certain individuals, this phenotypic variation was largely induced by the weather. Microscopically, its basidiospores are mostly elongate-ellipsoid, but distinct larger basidiospores present and probably discharged from bisporic basidia measured 10.5–11.1–12.0 × (4.0) 5.0–5.2–6.0 µm (n = 21). The cylindrical cheilocystidia are striking and very abundant, a character that is atypical to the genus. Mallocybe errata (E. Horak, Matheny & Desjardin) Haelew, a tropical Asian species shares erected squamules in pileus and profile and size of basidiospores, but differs by its hazel brown to golden brown pileus, adnate to marinate-depressed lamellae, more robust stipe measured 10–35 × (3) 4–8 mm, and broadly clavate to vesiculose cheilocystidia (Horak et al. 2015). Phylogenetically, M. longicystis is sister to another new species M. aurantiodisca discovered in subtropical China and shares a similar outline and size of basidiospores (see description of M. aurantiodisca). However, the latter species has reddish orange tinged pileus with tomentose squamules, less cylindrical cheilocystidia, and occurring in subtropical evergreen broad-leaved forests dominated by Castanopsis.
Mallocybe pallidipes Y.G. Fan, J.H. Hu & W.J. Yu, sp. nov., Figs. 4–5
MycoBank: MB844271
Etymology
pallidipes refers to its pallid stipe.
Diagnosis
differs from M. aurantiodisca by its isabelline pileus, pallid stipes, more cylindrical basidiospores, and an association with Populus.
Holotype: China, Jilin Province, Changchun City, in the campus of Jilin Agricultural University, 43°48ʹ16ʹʹN, 125°24ʹ07ʹʹE, 220 m asl., under Populus, 26 Jul 2019, Y.-G. Fan & W.-J. Yu, FYG3726 (FCAS3542), GenBank accession number: ITS (OM179924); LSU (OM137052) and RPB2 (OM835749).
Description
Basidiomata small-sized. Pileus 5–17 mm diam, hemispherical when young, becoming convex to broadly convex or upon expanding, plano-convex to undulate-applanate with age, obtusely umbonate at the disc; margin initially inflexed, then depressed to straight with age; surface dry, fibrillose-tomentose to woolly tomentose with scurfy appressed squamules, not rimose; dirty-yellowish (5B3), brownish yellow (5B4), or ochraceous brown (5B6), darker around the center, paler outwards. Lamellae 3–5 mm wide, adnexed-emarginate, moderately crowed, alternated with 3–4 tiers of lamelullae; initially pale yellowish white (5A3) or pale grayish white (5B2), then yellowish brown (5B4) to brown (5B5) with age; edges pallid and fimbriate. Stipe 14–28 × 1–3 mm, cylindrical, solid at first, then becoming fistulose, beige (5A2) or yellowish white (5B4), sometimes concolorous with pileus; equal, dry, silky from veil remnants. Context dirty white (5A2) and fleshy in pileus, 1–2 mm wide at mid-radius, fleshy-fibrillose and shiny in stipe. Odor unpleasant, somewhat bitter.
Basidiospores [100/4/2] (9.2)10.1–11.3–13.1(13.4) × (4.2)4.3–5.0–5.2(5.8) µm, Q = (1.88)2.00–2.65(2.84), Qm ± SD = 2.30 ± 0.020, smooth, thick-walled, yellowish to yellowish brown, very variable in shape, ellipsoid to subphaseoliform, sometimes phaseoliform in side view. Basidia 20–33 × 5–9 µm, clavate to slenderly clavate, necropigmented, 4-spored, sometime 2-spored, with inner olivaceous guttulae; sterigmata 3–5 mm long. Pleurocystidia absent. Lamellae edge sterile. Cheilocystidia 38–65 × 7–14 µm (n = 50), abundant, clavate to slenderly clavate, fusiform or utriform, apex rounded or slightly tapered, base truncate or tapered, colorless and hyaline, thin-walled. Hymenophoral trama 262–735 µm thick, regular to subregular, light yellowish, trama elements 11–16 µm wide, cylindrical to inflated or concave, thin-walled, smooth, hyaline. Stipitipellis a cutis often with extending hyphae, pale yellowish when aggregated, composed of cylindrical expanded hyphae, 6–10 µm wide, encrusted, hyaline. Stipe trama densely arranged, light yellowish when aggregated, composed of smooth, cylindrical hyphae, colorless, 6–11 µm wide. Caulocystidia absent. Pileipellis 90–122 µm thick, a cutis with emerging bundles of hyphae, golden yellow to yellowish brown when aggregated, composed of cylindrical to inflated and encrusted hyphae, 8–18 µm wide, slightly thick-walled, pale yellowish. Pileal trama hyaline, subregular, 300–560 µm thick, composed of several barbell cells or expanded cells of different sizes, 8–16 µm wide. Oieiferous hyphae exist in pileal and stipe trama, hyaline, 2–5 µm wide, with oval or spherical intracellular substances. Clamp connections present in all tissues.
Habitat
solitary and scattered along roadsides on clay soil under Populus.
Distribution
Known only from the type locality in Jilin Province, China.
Specimen examined
CHINA. Jilin Province, in the campus of Jilin Agricultural University, 43°48ʹ16ʹʹN, 125°24ʹ07ʹʹE, 220 m asl., under Populus, 26 Jul 2019, Y.-G. Fan & W.-J. Yu, FYG3727 (FCAS3543).
Remarks
Mallocybe pallidipes is a rare species collected in the Botanic Garden of Jilin Agricultural University, where there is a temperate climate. It occurs on the roadsides on clay soils in plantations of Populus and shrubs. The new species is characterized by Isabella-colored pileus with finely tomentose squamules, pallid stipe with fibrillose-fleshy context, dirty yellowish lamellae, and a bitter smell. Microscopically, its large cylindrical basidiospores, and cylindrical to fusiform cheilocystidia are distinct. Distinct large spores probably discharged from bisporic basidia are unfrequently observed and measured 12–12.4–14 × 4–4.8–6 µm (n = 27). Mallocybe aurnatiodisca is similar in having finely squamules in pileus, pallid stipes, cylindrical basidiospores outlines, and elongate cheilocystidia, but differs by its reddish orange tinged basidiomata, narrower lamellae, smaller basidiospores, and ecology in a subtropical forest. Mallocybe unicolor (Peck) Matheny & Esteve-Rav. originally described from New York shares subdistant lamellae, fibrillose-fleshy context in stipes, elongate-ellipsoid basidiospores, and long cheilocystidia, but differs by slightly broader basidiospores measured 10–13 × 5–6 µm and most cylindrical to cylindrical-flexuose cheilocystidia (Kuo 2017). Mallocybe pallidotomentosa E. Ludw., a European species described from Germany, is similar in outwards appearance and occurs under Populus and Betula, but it differs in smaller and often phaseoliform basidiospores measured 6.5–9.5 × 4–5 µm and mostly catenate cheilocystidia (Ludwig 2017).
Mallocybe aurantiodisca Y.G. Fan, J.H. Hu, W.J. Yu, Y.P. Ge & W.F. Lin, sp. nov., Figs. 6–7
MycoBank: MB844273
Etymology
aurantiodisca (Latin) refers to the orange tinge on pileus.
Diagnosis
differs from M. longicystis by its reddish orange pileus with finely tomentose squamules and shorter cheilocystidia.
Holotype: CHINA. Zhejiang Province, Lishui City, Liandu District, 28°26ʹ9ʹʹN,119°54ʹ14ʹʹE, 59 m asl., Under forest dominated by Pinus, 3 Jun. 2020.Y.-P. Ge & Q. Na, NJ3396 (FCAS3545), GenBank accession number: ITS (OM179936); LSU (OM138835) and RPB2 (OM835752).
Description
Basidiomata small-sized. Pileus 13–25 mm diam, convex when young, becoming plano-convex to broadly convex or upon expanding, becoming plano-convex to undulate-applanate with age, obtusely umbonate at the disc, margin initially inflexed, then deflexed, fibrillose-tomentose to woolly tomentose with scurfy appressed squamules, not rimose; initially brownish with orange tinge (6B4) or orange (6B5) to reddish brown (6B6), becoming pale yellow brown (6C6) or pale ochraceous yellow with orange tinge (6C7) at least around the disc. Lamellae 1–3 mm wide, adnate, narrow, initially pale greyish white (6B2), becoming yellowish white (6B4) to ochraceous brown (6C5), edge whitish (6B3) and fimbricate. Stipe 24–30×2–3 mm, cylindrical or slightly tapering towards base, solid at first, then becoming fistulose, dirty white (6A2) to pale yellow (6B5), surface fibrillose with appressed velar remnants, white (6A1) towards the base for the presence of a white (6A1) velipellis, whitish (6A1) cortina present in young basidiomes. Context creamy white (6B2) or pale yellowish white (6A2) in pileus, 1‒2 mm thick, concolorous in stipe. Odor indistinct.
Basidiospores [100/5/3] (7.9)8.1–9.1–10.2 (11.8) × (4.1)4.2–5.0–5.4 (6.2) µm, Q = (1.52) 1.58–2.13 (2.29), Qm ± SD = 1.85 ± 0.016, smooth, thick-walled, yellowish, thick-walled, ellipsoid, elongate ellipsoid to subphaseoliform. Basidia 27–38 × 6–10 µm, clavate to narrowly clavate, 4-spored, sometimes 2-spored, necropigmented, sterigmata up to 3–4 mm long. Pleurocystidia absent. Lamellae sterile. Cheilocystidia 28–62 × 6–18 µm (n = 52), mean 41 × 11 µm, abundant, subfusiform, subclavate, clavate to slenderly clavate, sometimes fusiform or cylindrical, septate and often constricted at septa, hyaline, thin-walled, Hymenophoral trama 92–141 µm, regular to subregular, colorless or somewhat yellowish, trama elements 13–20 µm wide, inflated or concave, cylindrical, thin-walled, hyaline. Stipipellis a cutis often with extending hyphae, yellowish when aggregated, composed of cylindrical expanded hyphae, 4–8 µm wide, encrusted, yellowish. Stipe trama densely arranged, light yellowish when aggregated, composed of smooth cylindrical hyphae, colorless, 5–8 µm wide. Caulocystidia absent. Pileipellis a cutis often with emerging bundles of hyphae, 98–225 µm thick, brownish to yellowish brown when aggregated, composed of cylindrical to expanded shell hyphae, 9–18 µm wide, slightly thickened, pale yellowish. Pileal trama 246–425 µm thick, hyaline, composed of several barbell-shaped cells or expanded cells of different sizes. Oieiferous hyphae 3–5 µm wide, hyaline, present in the epidermis of pileus and the stipe trama, exist oval or spherical substances. Clamp connections present in all tissues.
Habitat
solitary or scattered on clay soils under subtropical evergreen broad-leaved forest dominated by Castanopsis.
Distribution
Known from the two localities in Zhejiang Province, China.
Specimen examined
China, Zhejiang Province, Lishui City, Liandu District., 28°30ʹ5ʹʹN,119°42ʹ35ʹʹE, 166.4 m asl.. in evergreen broad-leaved forests dominated by Fgaceae trees, 4 Aug 2021, Q. Na, NJ3109 (FCAS3544); Hangzhou City, Yutang District, 866 Hangtang Road, Campus of Zhejiang University, 30°18ʹ33ʹʹN,120°5ʹ27ʹʹE, 666 m asl., under mixed broad-leaved forest, 3 Jun. 2020, W.-F. Lin, 2020ZD01 (FCAS3546).
Remarks
The new species is known so far from two localities in Zhejiang Province of China, where there is a subtropical monsoon climate. It occurs on clay soils in a subtropical evergreen broad-leaved forest dominated by Castanopsis and on the campus of Zhejiang University. Mallocybe aurantiodisca is characterized by its reddish orange tinged basidiomata, tomentose-squamulose pileus, elongate-ellipsoid basidiospores, utriform, ventricose to cylindrical cheilocystidia that is usually flexuous. Phylogenetically, it is sister to M. longicystis, another new species discovered in tropical China. Both the two species share similar-sized basidiospores. However, the latter has umber colored pileus with erected squamules and more elongate cheilocystidia (see descriptions of M. longicystis).