Research Article |
Corresponding author: Ursula Eberhardt ( ursula.eberhardt@smns-bw.de ) Academic editor: María P. Martín
© 2021 Ursula Eberhardt, Nicole Schütz, Henry J. Beker, Su See Lee, Egon Horak.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Eberhardt U, Schütz N, Beker HJ, Lee SS, Horak E (2021) Hebeloma in the Malay Peninsula: Masquerading within Psathyrella. MycoKeys 77: 117-141. https://doi.org/10.3897/mycokeys.77.57394
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In 1994 Corner published five new species within the genus Psathyrella, all having been collected on the Malay Peninsula between 1929 and 1930. Three of these species belong to the genus Hebeloma and with their vinaceous colored lamellae and spore print, when fresh, they belong to H. sect. Porphyrospora. Of these three species, only one, P. flavidifolia, was validly published and thus we herewith recombine it as H. flavidifolium. The other two species, P. splendens and P. verrucispora, are synonyms of H. parvisporum and H. lactariolens, respectively. We also describe a new Malayan species, H. radicans, which also belongs to H. sect. Porphyrospora. These findings confirm the western Pacific Rim as a diversity hotspot for H. sect. Porphyrospora. The records described within this paper, represent the first recognition that the genus Hebeloma, and indeed that members of the ectomycorrhizal Hymenogastraceae, are present on the Malay Peninsula.
Anamika, Agaricales, Dipterocarpaceae, ectomycorrhiza, Fagaceae, taxonomy, tropical forests
Only a small number of Hebeloma species have been described from Asia, most recently H. parvisporum from Laos (
The geographical distribution of species within H. sect. Porphyrospora is remarkable. The majority of the species occur in the western Pacific Rim region, with the exception of two species, H. porphyrosporum, to date only known from Europe, and H. sarcophyllum, to date only recorded from eastern North America (
During the course of this research, and our efforts to find relevant information about Hebeloma recorded from the Malay Peninsula, we came across a paper by E.J.H. Corner (1993), effectively published 1994 (
It is now clear that these three species belong to the genus Hebeloma. Based on the spore color in fresh material, they are members of H. sect. Porphyrospora. Unfortunately, the publication of two of these species is invalid under Art. 40.7 of the International Code (
It does appear that two of these three species, Psathyrella splendens and P. verrucispora, have been described and classified within Hebeloma since Corner’s publication, as H. parvisporum and H. lactariolens, originally published as Alnicola lactariolens. The third taxon, P. flavidifolia is recombined here as H. flavidifolium. Within this paper we cite seven new Hebeloma collections from the Malay Peninsula, collected by one of the authors (E. H.) during 2009 and 2010. Three of these collections are referred to H. lactariolens, one to H. parvisporum, two to H. flavidifolium and one to a species here described as new, H. radicans. All collections are from mixed tropical lowland forests dominated by Dipterocarpus, Quercus and Lithocarpus.
Basidiomes were collected, dried and accessioned at the fungus herbarium of the Forest Research Institute Malaysia (
Sequence data were obtained from dried specimens by direct sequencing following methods detailed in
Flammula alnicola was used for rooting, and two species of Alnicola [Naucoria fide Species Fungorum (Index Fungorum Partnership 2019) accessed 13 Dec 2019] (A. amarescens and A. salicis) were used as additional outgroups. Members of the genus Hebeloma are represented by material, including type material, used in earlier publications (
Sequences used in the analysis. Herbarium abbreviations follow Index Herbariorum and are given in capital letters followed by a space or hyphen and the herbarium number. Private collections are indicated by the lack of a space between the letters and numbers. MO refers to https://mushroomobserver.org/
Species | Country | HJB database reference | Voucher | GenBank acc. no. ITS | GenBank acc. no. MCM7 |
---|---|---|---|---|---|
Alnicola amarescens (Quél.) R. Heim & Romagn. | Switzerland | HJB11116 | HJB11116 | MK961996† | MK961952† |
Alnicola salicis (P.D. Orton) Bon | U.K. | HJB14745 | HJB14745 | MK962001† | MK961960† |
Flammula alnicola (Fr.) P. Kumm. | Germany | – | GLM-F045994 | MK957190† | MK961971† |
Hebeloma aestivale Vesterh. | U.K. | HJB9291 | HJB9291 | KT218221‡ | MK961944† |
H. alboerumpens Vila & al. | Spain | HJB13021 | JVG1090114-15 | JQ751220§ | JQ751104§ |
H. alpinum (J. Favre) Bruchet | Switzerland | HJB11132 | HJB11132 | KM390590| | KM390046| |
H. aminophilum R.N. Hilton & O.K. Mill. | New Zealand | HJB10682 | PDD 102982 (PL14504) | MK961993† | MK961949† |
H. aminophilum | Australia | HJB16823 | HO 586929 | MK962007† | MK961966† |
H. aminophilum f. hygrosarx B.J. Rees | Australia | HJB1000297 | PERTH 06659152 | MK962016† | MK961969† |
H. angustilamellatum (Zhu L. Yang & Z.W. Ge) B.J. Rees | China | HJB1000408 | HKAS 42927 | AY575919¶ | – |
H. angustilamellatum | Thailand | HJB12251 | GENT RW07-470 | MK961997† | MK961953† |
H. angustilamellatum | Laos | HJB14851 | HNL 501000 | MK962003† | MK961962† |
H. angustilamellatum | Laos | HJB17006 | HNL 501053 | MK962010† | – |
H. bulbiferum Maire | Croatia | HJB13083 | TUR-A 177060 | KT218422‡ | MK961956† |
H. cavipes Huijsman | Spain | HJB9433 | HJB9433 | KT217362# | KT216685# |
H. celatum Grilli, U. Eberh. & Beker | Germany | HJB13621 | BR 5020184119676 | KT218446‡ | MK961957† |
H. crustuliniforme (Bull.) Quél. | Spain | HJB11237 | HJB11237 | JN943870†† | KF309440| |
H. cylindrosporum Romagn. | Spain | HJB11427 | C-F-44748 | FJ769365‡‡ | MT832328 |
H. cylindrosporum | France | HJB12763 | HJB12763 | JQ751210§ | JQ751106§ |
H. dunense L. Corb. & R. Heim | Belgium | HJB14141 | AdH11031 | KY271835§§ | MK961959† |
H. flavidifolium | Malaysia | HJB13504 | E. Horak 13404 ( |
MT832021 | – |
H. flavidifolium | Malaysia | HJB13505 | E. Horak 13406 ( |
MT832022 | – |
H. ifeleletorum Kropp | American Samoa | HJB1000386 | UTC 00235643 | MK962019† | MK961970† |
H. indicum (K.A. Thomas & al.) B.J. Rees | India | HJB1000384 | IB 19971307 | AF407163|| | – |
H. indicum | India | HJB12902 | IB 19991200 | MK961999† | MK961955† |
H. khogianum Bresinsky | New Caledonia | HJB1000388 | M-0124631 | GU591635¶¶ | – |
H. lactariolens Clémençon & Hongo) B.J. Rees & Orlovich | Japan | – | LAU HC88/95 | AY818352¶ | – |
H. lactariolens | China | – | HMAS 280191 | KX513590††† | – |
H. lactariolens | Malaysia | HJB13363 | E. Horak 12796 ( |
MT832017 | MT832330 |
H. lactariolens | Malaysia | HJB13365 | E. Horak 13287 ( |
MT832019 | – |
H. lactariolens | Malaysia | HJB13503 | E. Horak 13381 ( |
MT832020 | MT832331 |
H. laterinum (Batsch) Vesterh. | France | HJB13703 | HJB13703 | MK962000† | MK961958† |
H. mediorufum Soop | New Zealand | HJB10689 | PDD 102983 (PL51404) | KM390552| | KM390037| |
H. mediorufum | New Zealand | HJB10688 | PDD102995 (PL167404) | KM390572| | KM390042| |
H. mesophaeum (Pers.) Quél. | Iceland | HJB11050 | HJB11050 | MK961995† | MK961951† |
H. parvisporum Sparre Pedersen & al. | Laos | HJB14850 | HNL 501009 | MK962002† | MK961961† |
H. parvisporum | Laos | HJB14852 | HNL 500968 | MK962004† | MK961963† |
H. parvisporum | Laos | HJB17004 | HNL 500914 | MK962008† | – |
H. parvisporum | Laos | HJB17005 | HNL 500984 | MK962009† | – |
H. parvisporum | Laos | HJB17007 | HNL 500884 | MK962011† | – |
H. parvisporum | Malaysia | HJB13362 | E. Horak 12795 ( |
MT832016 | – |
H. plesiocistum Beker & al. | Spain | HJB11514 | JVG1021214-5 | EU570170‡‡‡ | JQ751115§ |
H. porphyrosporum Maire | Italy | HJB10344 | HJB10344 | MK961992† | MK961947† |
H. porphyrosporum | Spain | HJB10767 | HJB10767 | MK961994† | MK961950† |
H. radicans | Malaysia | HJB13364 | E. Horak 13265 ( |
MT832018 | – |
H. radicosum (Bull.) Ricken | Belgium | HJB10262 | HJB10262 | MK961990† | MK961945† |
H. radicosum | Italy | HJB10314 | HJB10314 | MK961991† | MK961946† |
H. sarcophyllum (Peck) Sacc. | U.S.A. | HJB15696 | DPL 10569 | MK962005† | MK961964† |
H. sarcophyllum | U.S.A. | HJB17783 | MO301904 | MK962014† | – |
H. sinapizans (Paulet) Gillet | U.K. | HJB10628 | HJB10628 | JQ751191§ | JQ751119§ |
H. sinapizans | U.K. | HJB10751 | HJB10751 | JQ751193§ | JQ751121 |
H. subvictoriense B.J. Rees | Australia | HJB1000299 | MEL 2331640 | MK962017† | – |
H. syrjense (P. Karst.) P. Karst. | France | HJB12064 | HJB12064 | JQ751206§ | JQ751122§ |
H. syrjense | Finland | HJB12396 | C 26197F | JQ751218§ | JQ751123§ |
H. theobrominum Quadr. | Estonia | HJB10009 | HJB10009 | EU570181‡‡‡ | JQ751124 |
H. theobrominum | Belgium | HJB10063 | HJB10063 | FJ816623§§§ | JQ751125§ |
H. vaccinum Romagn. | Belgium | HJB9965 | HJB9965 | KT217371# | KT216689# |
H. velutipes Bruchet | France | HJB10547 | HJB10547 | EU570174‡‡‡ | MK961948† |
H. velutipes | U.K. | HJB10483 | HJB10483 | EU570175‡‡‡ | MT832329 |
H. vesterholtii Beker & U. Eberh. | Italy | HJB10339 | HJB10339 | FJ816629, FJ816630§§§ | JQ751132 |
H. vesterholtii | Italy | HJB11869 | HJB11869 | FJ943239, FJ943240§§§ | JQ751135§ |
H. victoriense A.A. Holland & Pegler | New Zealand | HJB12401 | PDD 93802 (PL3408) | MK961998† | MK961954† |
H. victoriense | Australia | HJB16704 | HO 586713 | MK962006† | MK961965† |
H. vinosophyllum Hongo | Japan | HJB17411 | MO287712 (UK323) | MK962012† | MK961967† |
H. vinosophyllum | Japan | HJB17413 | MO299315 (UK347) | MK962013† | MK961968† |
H. westraliense Bougher & al. | Australia | HJB1000134 | PERTH 01012665 | MK962015† | – |
H. youngii B.J. Rees | Australia | – | MEL 2382694 | KP012873||| | – |
H. youngii | Australia | HJB1000343 | BRI AQ669300 | MK962018† | – |
Sequence alignments were done online in mafft using the E-INS-i option (
The compatibility of the two loci was accessed following the principle of
The datasets were then concatenated and subdivided into five partitions, ITS and four MCM7 partitions, the exon in three partitions by codon position and the intron. In IQ tree 2.0.6, the best partitioning scheme and the best likelihood models were determined under the Bayesian information criterion (
A Bayesian inference (BI) analysis was run with mrbayes 3.2.6 (
Trees were visualized using FigTree 1.4.4 (
Details of morphological analyses were provided in
We obtained ITS data for all recent collections from Malaysia and in addition MCM7 data for Malaysian H. lactariolens. No sequence information could be obtained from Corner’s material. The datasets included 68 ITS and 49 MCM7 sequences (Table
The concatenated dataset included 1439 sites that were analyzed in three partitions with three different models (ITS: GTR+F+I+G4; MCM7 1st and 3rd position: K3P+I; MCM7 2nd and intron: K2P+I) in the ML tree reconstruction. Bootstrap support was based on 500 replicates. The topology of the ML tree is shown in Fig.
All of the Malaysian collections are included in the clade corresponding to H. sect. Porphyrospora and there within the western Pacific rim clade. The clade of the species H. flavidifolium received full bootstrap and posterior probability support as does the clade of H. parvisporum. In the ML reconstruction, Hebeloma lactariolens is paraphyletic in relation to the sequences of the Oceanic species H. youngii, which are monophyletic and receive full support. In the BI result, H. lactariolens is monophyletic, but unsupported and in a weakly (0.96 posterior probability) supported sister clade relationship with the clade of H. angustilamellatum, H. flavidifolium, H. ifeleleretorum and the H. indicum clade. The Malaysian collections that we refer to as H. flavidifolium, H. lactariolens, and H. parvisporum (Fig.
ML topology of concatenated ITS and MCM7 sequences of Hebeloma and Alnicola. Flammula alnicola is used for rooting purposes. Bootstrap support based on 500 replicates and posterior probabilities based on a BI analysis are indicated at the branches. Assignment of species to sections follows
We include four species collected from the Malay Peninsula. Three of these have previously been described as Psathyrella. Two of these species, P. splendens and P. verrucispora, were invalidly published but have since been validly published within Hebeloma, as H. parvisporum and H. lactariolens, respectively. The third of these species, Psathyrella flavidifolia was validly published and here we recombine it as a Hebeloma. Finally, we describe a fourth Hebeloma from the Malay Peninsula, Hebeloma radicans, as new.
Basionym. Psathyrella flavidifolia Corner, Gdns’ Bull., Singapore 45(2): 339 (1994) [“1993”].
Lacrymaria flavidifolia (Corner) Voto, Boll. Assoc. micol. ecol. Romana 107(2): 94 (2019).
Malaysia. Pahang State: Raub district, Bukit Fraser (Fraser’s Hill), ca. 1200 m a.s.l., Quercus woodland, 25 Nov 1930, E.J.H. Corner (holotype: E! [E 00204812]; database reference HJB19600).
Basidiomes scattered. Pileus 35–105 mm wide, convex to broadly umbonate; surface dry, sometimes rugulose, occasionally striate at the margin, usually with veil remnants on the margin; cuticle color predominantly cinnamon brown to orange brown (6C5, 7C7) in the center with paler margin, dark beige to tan (5B3); pileus margin strongly involute when young, hygrophanous. Lamellae adnate, often with decurrent tooth, 2–3 mm broad, crowded, thin, with approx. 80–90 full length lamellae and 2–3 lamellules between the lamellae, off-white to cream or yellow-grey when young, later becoming more pinkish or grayish red to purplish and eventually vinaceous to purple-brown or brown following spore maturity; edges weakly fimbriate and white; the white edge remains when the basidiome is dried but the reddish brown color of the lamellae disappears with time. Stipe 50–120 mm long and with central width 5–12 mm, cylindrical sometimes tapering or clavate towards the base, not rooting, occasionally with mycelial cords at the base; white or alutaceous; surface dry, fibrillose, pruinose in the upper part, not discoloring with handling, becoming hollow with age. Flesh whitish, hardly discoloring where bruised. Odor indistinct to raphanoid; taste bitter. Spore vinaceous cinnamon becoming chocolate brown. Exsiccata with no particular characteristics.
Basidiospores based on at least 50 spores from each of three collections, 5% to 95% percentile range 8.9–11.4 × 5.6–7.1 µm, with median 9.7–10.6 × 6.1–6.7 µm and av. 9.6–10.6 × 6.1–6.6 µm with av. S. D. length 0.47 µm and width 0.33 µm; Q value 5% to 95% percentile range 1.43–1.72, with median 1.53–1.58 and av. 1.53–1.59 with av. S. D. 0.07; amygdaloid, occasionally limoniform with small apiculus and rounded apically, with a distinct thinning of the apical wall, without guttules, usually very strongly ornamented, warty, with a strongly and distinctly loosening perispore on almost every mature spore and strongly dextrinoid, becoming medium brown in Melzer’s reagent, sometimes deep brown, ((O3) O4; P3; D3 (D4)); spore color under the light microscope distinctly brown. Basidia av. dimensions 19–33 × 6–9 µm, cylindrical to clavate, without pigmentation, 4-spored. Cheilocystidia irregular, cylindrical to ventricose, often pyriform or napiform often mucronate or rostrate, even lanceolate (as shown in Fig.
So far known only from Bukit Fraser (Fraser’s Hill), Malaysia.
The recent collections were found scattered in lowland dipterocarp-oak woodland on the side of the path in tropical rain forest with Quercus.
Malaysia. Pahang State: Raub district, Bukit Fraser (Fraser’s Hill), Jalan Girdle, ca. 1000 m a.s.l., 3.71°N, 101.74°E, Quercus woodland, 26 Apr. 2010, E. Horak 13406 (collection E. Horak at
Given Corner’s original description almost totally lacked any microscopic information, we present a full description here based on the holotype plus two more recent collections from roughly the same location, both collected by E. Horak. Morphologically, this species most closely resembles Hebeloma angustilamellatum, originally described from the Yunnan province of China (
Microscopic features of Hebeloma flavidifolium holotype (E 00204812) A spores in Melzer’s reagent ×1600 B spore ornamentation in Melzer’s reagent ×1600 C cheilocystidia in Melzer’s reagent ×500 D cheilocystidia in Melzer’s reagent ×1000 E cheilocystidia in KOH ×1000 F pleurocystidia in KOH ×1000. Scale bars: 10 µm (A–F). Photographs H.J. Beker. G Exsiccata (a section of photograph from http://data.rbge.org.uk/herb/ E 00204812 provided by the Royal Botanic Garden Edinburgh).
Microscopic features of Hebeloma flavidifolium (E. Horak 13406) A spores in Melzer’s reagent ×1600 B spore ornamentation in Melzer’s reagent ×1600 C cheilocystidia in KOH ×500 D cheilocystidia in KOH ×1000 E basidium in KOH ×1000 F pleurocystidia in KOH ×1000 G caulocystidium in KOH ×1000 H ixocutis section (showing thin gelatinous epicutis) in KOH ×125 I epicutis hyphae in KOH ×500 J subcutis below epicutis in KOH ×500. Scale bars: 10 µm, 100 µm (H). Photographs H.J. Beker.
Japan. Shiga-ken: Otsu-shi, Tomikawa, ca. 180 m a.s.l., 34.9001°N, 135.9489°E, Pinus sp., Quercus sp., 15 Aug 1988, T. Hongo, H. Clémençon HC88/95 (holotype TNS! [TNS-F-237670]; isotype LAU; database reference HJB1000383; ITS GenBank acc. no. AY818352).
Alnicola lactariolens Clémençon & Hongo, Mycoscience 35(1): 25 (1994). Anamika lactariolens (Clémençon & Hongo) Matheny, Mycol. Res. 109(11): 1262 (2005).
Psathyrella verrucispora Corner, Gdns’Bull., Singapore 45(2): 344 (1994) [1993], nom. inval., Art. 40.7 ≡ Lacrymaria verrucispora (Corner) Voto, Boll. Assoc. micol. ecol. Romana 107(2): 95 (2019), nom. inval., Art. 40.7. Type: Singapore. Malay Peninsula, Aug. 1929, E.J.H. Corner (holotype E! [E 00204780]; database reference HJB19598).
Malaysia. Johor State: Mersing district, Endau-Rompin Selai, Endau-Rompin (Johor) National Park, Camp Lubuk Tapah, ca. 130 m a.s.l., 2.2976°N, 103.1351°E, with Dipterocarpus, 19 Mar. 2009, E. Horak 12796 (collection E. Horak at
This species is rather variable molecularly and in the ML reconstruction forms a clade together with H. youngii, an Australian species growing with Eucalyptus and Corymbia, to our knowledge only known from the type locality (
Microscopic features of Hebeloma lactariolens (E 00204780); intended holotype of Psathyrella verrucispora nom. inval.) A spores in Melzer’s reagent ×1600 B spore ornamentation in Melzer’s reagent ×1600 C basidium in KOH ×1000 D cheilocystidia in KOH ×1000 E, F pleurocystidium in KOH ×1000 G caulocystidia in KOH ×500 H sectional view of cutis below the gelatinous epicutis in KOH ×500 I sectional view of ixocutis showing thin gelatinous epicutis in KOH ×125. Scale bars: 10 µm (A–H), 100 µm (I). Photographs H.J. Beker. J Exsiccata (a section of photograph from http://data.rbge.org.uk/herb/E00204780 provided by the Royal Botanic Garden Edinburgh).
Laos. Xieng Khouang: Phoukhout, Laethong, ca. 1135 m a.s.l., 19.742408°N, 103.258102°E, on soil under Fagaceae, 18 Aug 2015, T. Læssøe, O.S. Pedersen (holotype: HNL [HNL 500968]; isotype: C! [C-F-122153]; database reference HJB14852; ITS GenBank Acc. No.: MK962004).
Psathyrella splendens Corner, Gdns’ Bull., Singapore 45(2): 341 (1994) [“1993”], nom. inval., Art. 40.7 ≡ Lacrymaria splendens (Corner) Voto, Boll. Assoc. micol. ecol. Romana 107: 95 (2019), nom. inval., Art. 40.7. Type. Singapore. Malay Peninsula, 9. Mar 1930, E.J.H. Corner (holotype: E! [E 00204835]; database reference HJB19597).
Laos. Xiang Khouang: Khoun, Thoum, ca.1130 m a.s.l., 19.314945°N, 103.409749°E, under Fagaceae, 20 Aug. 2015, T. Læssøe, O.S. Pedersen (HNL [HNL 501009]; database reference HJB14850); Xiang Khouang: Paek, Phonekham, ca.1125 a.s.l., 19.494286°N, 103.269110°E, under Fagaceae, 16 Aug. 2015, T. Læssøe, O.S. Pedersen (HNL [HNL 500914]; database reference HJB17004); Xieng Khouang, Phoukhout, Ban Bong, ca.1150 m a.s.l., 19.672180°N, 103.135841°S, under Fagaceae 15 Aug. 2015, T. Læssøe, O.S. Pedersen (HNL [HNL 500884]; database reference HJB17007); Xieng Khouang, Phoukhout, Sui, ca. 1150 m a.s.l., 19.530514°N, 102.8659°E, under Fagaceae, 19 Aug. 2015, T. Læssøe, O.S. Pedersen (HNL [HNL 500984]; database reference HJB17005). MALAYSIA. Johor State, Mersing district, Endau-Rompin Selai, Endau-Rompin (Johor) National Park, Camp Lubuk Tapah, ca. 130 m alt., 2.2976°N, 103.1351°E, with Dipterocarpus, 19 Mar 2009, E. Horak 12795 (collection E. Horak at
The description of this species (
The collection cited as holotype for P. splendens was collected in Singapore while Corner also cites other collections from Singapore and Malaysia (
Microscopic features of Hebeloma parvisporum (E 00204835; intended holotype of Psathyrella splendens nom. inval.) A spores in Melzer’s reagent ×1600 B spore ornamentation in Melzer’s reagent ×1600 C, D cheilocystidia in KOH ×1000 E cheilocystidia and basidium in KOH ×500 F caulocystidia, in KOH ×1000. Scale bars: 10 µm. Photos H.J. Beker. G Exsiccata (a section of photograph from http://data.rbge.org.uk/herb/E00204835, provided by the Royal Botanic Garden Edinburgh).
The combination of a deeply rooting stipe, about 60 full length lamellae (from stipe to margin of pileus) and spores where almost every spore has a strongly loosening perispore forming a clear layer around the spore, separate this taxon from all other members of H. sect. Porphyrospora, as does the ITS-sequence.
Malaysia. Johor State: Kluang district, Endau-Rompin Peta, Endau-Rompin (Johor) National Park, Kampung-Peta, trail to Kuala Marong, ca. 50 m a.s.l., 2.52°N, 103.36°E, on soil in lowland dipterocarp-oak forest, 3 Sept 2009, E. Horak, 13265 (holotype: collection E. Horak at
Basidiomes scattered. Pileus 37–64 mm wide, convex to broadly umbonate; surface dry or slightly viscid, without veil remnants on the pileus; cuticle color predominantly cream to pale buff (4A3, 4A4) in the center with paler margin, off-white to pale cream (4A2); pileus margin entire, hygrophanous. Lamellae adnate, moderately dense, thin, with approx. 60 full length lamellae and 2–3 lamellulae between the lamellae, off-white to cream when young, later pinkish or grayish red to purplish and eventually vinaceous to purple-brown following spore maturity; edges weakly fimbriate and white; the white edge remains when the basidiome is dried but the reddish brown color of the lamellae disappears with time. Stipe 160–194 mm long (including the ‘root’) and with central width 4–9 mm, cylindrical, distinctly and deeply rooting, white or alutaceous; surface dry, fibrillose, pruinose in the upper part, discoloring with handling and age. Flesh whitish, hardly discoloring where bruised. Smell fragrant; taste bitter. Spore deposit porphyry-brown (10E4). Exsiccata with no particular characteristics.
Basidiospores based on n = 94 spores of the holotype, 5% to 95% percentile range 8.7–10.2 × 5.6–6.6 µm, with median 9.5 × 6.2 µm and av. 9.5 × 6.2 µm with S. D. length 0.47 µm and width 0.34 µm; Q value 5% to 95% percentile range 1.43–1.65, with median 1.53 and av. 1.54 with S. D. 0.07; amygdaloid, with small apiculus and rounded apically, with a distinct thinning of the apical wall and never any sign of papilla, without guttules, usually very strongly ornamented, warty, with a strongly and distinctly loosening perispore on almost every mature spore (almost forming a uniform layer around the spore and making measurement quite difficult at times) and very strongly dextrinoid, immediately becoming deep and intensely red-brown in Melzer’s reagent, (O4; P3; D4); spore color under the light microscope distinctly brown. Basidia 21–29 × 6–8 µm, with av. 24.3 × 7.2 µm, cylindrical to clavate, without pigmentation, 4-spored. Cheilocystidia ventricose, primarily pyriform often mucronate or rostrate with width near apex (excluding any rostrum) 5% to 95% percentile range 5–8 µm, with median 6.4 µm and av. 6.5 µm with S.D. 1.06; and av. overall measurements 24 × 6.5 × 9.9 × 8.3 µm av. Cheilocystidium av. ratios A/M: 0.66, A/B: 0.79, B/M: 0.84. Pleurocystidia present, and abundant, and similar to cheilocystidia. Caulocystidia resembling the pleurocystidia but tending to be more cylindrical and longer. Pileipellis an ixocutis with a very thin epicutis only about 20 µm thick, with gelatinized hyphae up to 5 µm wide. The cutis below the epicutis is orange-brown and the trama below the cutis is made up of isodiametric cells up to 25 µm wide. Clamp connections at septa present throughout the basidiome.
Only known from the type locality in Endau-Rompin (Johor) National Park, Malaysia.
Scattered in lowland dipterocarp-oak woodland on the side of the path.
From ‘radicans’, meaning rooting, to emphasize this character of the species.
Hebeloma radicans with its vinaceous colored lamellae when mature and the porphyry colored spore print which turns brown with time, is a typical member of H. sect. Porphyrospora. The highly ornamented and highly dextrinoid spores are often seen in taxa of this section; while the consistently loosening perispore is also a common feature of a number of the taxa within this section, the regularity and presentation of the perispore is atypical and very distinctive. The rooting stipe is also unusual; while we have recorded rooting stipes in other members of this section, namely: H. lactariolens, H. parvisporum, and H. victoriense, in these cases it is a shallow root occurring infrequently and not on every basidiome. The rooting stipe of H. radicans is deep and more reminiscent of H. radicosum. This long rooting stipe should be sufficient to distinguish this species from other described members of this section, but taken together with the spore properties and also the moderately dense (but not crowded) lamellae (approx. 60 full length lamellae), assuming these characters are constant, this taxon is clearly distinct. In Fig.
While, to date, we only have one collection of this species, given its morphological differences and molecular distinctness, we are confident that this taxon is different from any other described within Hebeloma and we hope that its publication will encourage its rediscovery. It is of course possible that it has been confused with other genera, e.g. Psathyrella, as was the case with other Malay Peninsula collections as described here, but thus far we have not been able to find any evidence of this.
Microscopic features of Hebeloma radicans holotype (E. Horak 13265) A spores in KOH ×1600 B spore ornamentation in KOH ×1600 C cheilocystidia and basidium in KOH ×1000 D cheilocystidia and basidium in KOH ×1000 E pleurocystidia in Melzer’s reagent ×1000 F basidia in KOH ×1000 G pleurocystidia in KOH ×500 H sectional view of ixocutis showing thin gelatinous epicutis in KOH ×125 I sectional view of subcutis and trama below subcutis in KOH ×500 J sectional view of trama below subcutis in KOH ×500. Scale bars: 10 µm, 100 µm (H). Photographs H.J. Beker.
Had the describers of Hebeloma parvisporum been aware of Psathyrella splendens, they would have used that epithet for H. parvisporum. When describing the species, other genera like Alnicola, Naucoria, and even Pholiota were checked for misplaced Hebeloma species (
We here demonstrate the presence of four, presumably endogenous species, of Hebeloma in tropical forests of the Malay Peninsula, a genus previously overlooked in this region. In the checklist for Malaysia (
Having said this, it should be noted that the authors of checklists for the Malay Peninsula (
The molecular results support earlier results of
The collections were made in the context of the Forest Research Institute Malaysia (