Hebeloma parvisporum Sparre Pedersen, Laessoe , Beker & U. Eberh., Mycologia 112: 179 (2020)

Eberhardt, Ursula, Schuetz, Nicole, Beker, Henry J., Lee, Su See & Horak, Egon, 2021, Hebeloma in the Malay Peninsula: Masquerading within Psathyrella, MycoKeys 77, pp. 117-141 : 117

Hebeloma parvisporum Sparre Pedersen, Laessoe, Beker & U. Eberh., Mycologia 112: 179 (2020) Figures 2C , 7

Type.

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).

Heterotypic synonyms.

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).

Other material examined.

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 ZT; database reference HJB13362).

Remarks.

The description of this species ( Eberhardt et al. 2020) was based upon the above collections from Laos. The intended holotype of P. splendens was examined and is micro- and macromorphologically in agreement with H. parvisporum ; this is illustrated in Fig. 7 which shows the main micro characters of Corner’s intended type. The collection from Malaysia is monophyletic with the Laos material. Molecularly, the species is most closely related to the Australian/New Zealand H. victoriense species group.

The collection cited as holotype for P. splendens was collected in Singapore while Corner also cites other collections from Singapore and Malaysia ( Corner 1994 [ “1993”]), to which we can add the Malaysian collection above. Plate 3 of Corner (1994 [ “1993”]) illustrates the species macroscopically; Lee (2017) includes a photograph of P. splendens from the FRIM forest and comments that it often grows in large clusters and is common in the FRIM forest and other parts of the country. The FRIM database includes additional records of this species (not studied) from: Endau-Rompin National Park, Johor; Fraser’s Hill, Pahang; the FRIM grounds, Kepong, Selangor; Pasoh, Negeri Sembilan and Tasik Bera, Pahang from lowland and hill dipterocarp forests and a planted dipterocarp forest. S.S.L. observed this species also in degraded hill dipterocarp forest in Janda Baik, Pahang. The species is not listed on the checklist of mushrooms in Thailand (Chandrariskul et al. 2011), but Felix Hampe (oral communication, 21 Jan 2020) reported it from Thailand (Chiang Mai Prov.). Thus, it appears that this species may be widespread within tropical Asia, associated with Fagaceae and dipterocarps ( Dipterocarpus ). In Laos, H. parvisporum is found for sale in the local markets for human consumption, but its synonym P. splendens is not listed among the species consumed in Malaysia ( Chang and Lee 2004; Samsudin and Abdullah 2019).

Figures

Figure 2. Macroscopic features A Hebeloma flavidifolium (E. Horak 13406) B H. lactariolens (E. Horak 13381) C H. parvisporum (E. Horak 12796) D H. radicans holotype (E. Horak 13265). Photographs E. Horak.

Figure 7. Microscopic features of Hebeloma parvisporum (E 00204835; intended holotype of Psathyrella splendens nom. inval.) A spores in Melzer's reagent x 1600 B spore ornamentation in Melzer's reagent x 1600 C, D cheilocystidia in KOH x 1000 E cheilocystidia and basidium in KOH x 500 F caulocystidia, in KOH x 1000. Scale bars: 10 µm. Photos H. J. Beker. G Exsiccata (a section of photograph from http: // data. rbge. org. uk / herb / E 00204835, provided by the Royal Botanic Garden Edinburgh).