Hebeloma neurophyllum G.F. Atk., Annales Mycologici 7(4): 370 (1909)

Eberhardt, Ursula, Kong, Alejandro, Montoya, Adriana, Schuetz, Nicole, Bartlett, Peter & Beker, Henry J., 2022, Not (only) poison pies - Hebeloma (Agaricales, Hymenogastraceae) in Mexico, MycoKeys 90, pp. 163-202 : 163

Hebeloma neurophyllum G.F. Atk., Annales Mycologici 7(4): 370 (1909)

Figs 11 , 12

Type.

USA. New York: Coy Glen, Ithaca , approx. 42.4272°N, 76.5241°W, alt. approx. 125 m, on soil in woodland, 18 Oct 1906, N. Coil (holotype CUP-A-021514; isotype TENN-F-037531, HJB1000453, isotype WTU-F-039596, HJB1000558) .

Diagnosis.

Gregarium 7-8 cm altum, pileo 5-6 cm lato, stipite 5-6 mm crasso: Pileo ochraceo-cremeo vel fulvo-ochraceo, leviter viscido. Lamellis 8 mm latis, pallide cinnamomeo-rufis, late sinuatis, adnexis, costatis. Basidiis 4-sporis. Sporis subfusoideis, 12-15 × 7-8 µ [m]. Ad terram in silvis, Ithacae, N. Y. Stipite albo, fibroso-striato, cavo vel subfarcto.

English translation of diagnosis.

Gregarious 7-8 cm high, pileus 5-6 cm broad, stipe 5-6 mm thick: pileus ochraceous-cream or fulvous-ochraceous, slightly viscid. Lamellae 8 mm broad, pale cinnamon-reddish, broadly sinuate, adnexed, intervenose. Basidia four-spored. Spores subfusoid, 12-15 × 7-8 μm. On the ground in woodland, New York. Stipe white, fibrous-striate, fistulose or almost stuffed.

Description.

Pileus (26) 30-55 (60) mm diameter, convex, occasionally umbonate or broadly umbonate; margin often smooth, occasionally involute or wavy, not hygrophanous; usually unicolor, occasionally two colors, at center occasionally yellowish brown, ochraceous or cream, rarely fawn, cinnamon or clay-buff, sometimes slightly paler towards margin. Lamellae usually emarginate, occasionally adnexed, depth up to 9 mm, white, cream to brown, usually with white fimbriate edge, usually without droplets on the lamella edge but rarely some drops may be visible, number of full-length lamellae 70-94. Stipe (25) 31-75 (80) mm long, 5-14 (16) mm diameter at median, often clavate or bulbous, occasionally cylindrical, (7) 9-16 (18) mm wide at base, surface cream, ivory, rarely discoloring, occasionally velutinous, floccose or fibrillose, often pruinose, particularly towards apex. Veil not observed. Context in pileus white to cream, firm, in stipe usually hollow, rarely with superior hanging wick; taste mild, smell occasionally raphanoid or odorless, rarely fruity or earthy. Spore deposit yellowish brown to brownish olive.

Basidiospores based on n = 70 spores of the holotype, 5% to 95% percentile range 12.7-15.6 × 7.2-9.0 µm, with median 14.2 × 8.2 µm and av. 14.2 × 8.2 µm with S.D. length 0.93 µm and width 0.54 µm; Q value 5% to 95% percentile range 1.52-1.91, with median 1.74 and av. 1.73 with S.D. 0.12; spore size based on 47 collections medians 11.6-14.3 × 7.2-8.2 µm and av. 11.7-14.2 × 7.5-8.3 µm with av. S.D. length 0.898 µm and width 0.459 µm, av. Q 1.53-1.78, amygdaloid, usually limoniform, with small apiculus and rounded apically, often subacute to acute, with a distinct thinning of the apical wall and a clear papilla, occasionally guttulate with one or sometimes more oily drops, distinctly to strongly ornamented (ornamentation visible without immersion), with a perispore somewhat to distinctly loosening, at least in a few spores, strongly dextrinoid, becoming at least medium brown and often intensely red-brown in Melzer’s reagent (O3/4; P1/2; D3/4); yellow to brown in KOH. Basidia 20-43 × 7-10 µm, with av. Q 2.7-3.8 µm, cylindrical to clavate, with a median constriction, hyaline, 4-spored. Cheilocystidium width near apex holotype 5% to 95% percentile range 4.9-9.0 µm, with median 6.5 µm and av. 6.7 µm with S.D. 1.27 µm; across 47 collections median 4.5-6.8 µm and av. 4.6-6.7 µm; examining approx. 20 selected cheilocystidia of each of the 47 collections yields a range for the avs of 40-59 × 4.6-6.7 × 4.4-5.7 × 5.6-8.4 µm and 49 × 6.7 × 5.6 × 6.7 µm av. for the holotype. Cheilocystidium av. ratios A/M: 1.01-1.41, A/B: 0.68-1.23, B/M: 1.16-1.58, mainly gently clavate or ventricose, occasionally cylindrical, lageniform or clavate-lageniform or clavate-ventricose, often with one or two septa, sometimes clamped, often with plaques on the cystidial walls, occasionally geniculate or with basal wall thickening, rarely bifurcate, hyaline, rarely with yellow contents. Pleurocystidia absent. Caulocystidia similar to cheilocystidia but larger, up to 115 μm long. Pileipellis an ixocutis, epicutis up to 90 µm thick, with gelatinized, hyphae up to 6 µm wide; subcutis pale yellow to brownish yellow, and the trama below the cutis made up of cylindrical, often ellipsoid cells, up to 16 µm wide. Clamp connections present throughout the basidiome.

Habitat and distribution.

Based on almost 50 collections, where only one possible associate was recorded, the most commonly recorded associates were Picea and Quercus , but Populus , Salix and Tilia were also recorded; the most commonly recorded families were Fagaceae, Pinaceae and Salicaceae, but Betulaceae and Malvaceae were also recorded. We have additional records where Alnus , Arctostaphylos , Betula , Dryas , Pinus and Polygonum were recorded as possible associates, but in each of these cases a number of possible associates were mentioned. All records of H. neurophyllum are from Northern America, where it is widespread across the region but primarily collected in temperate to boreal woodland, occasionally in urban areas.

Additional material examined.

Canada. Alberta: Moose Hill, Breton, Edmonton , 53.1418°N, 114.6097°W, alt. approx. 810 m, on soil in mixed woodland under Picea mariana , 12 Aug 2017, H. J. Beker ( HJB16856 ) . Northwest Territories: Highway 3, between Yellowknife and Behchoko , 62.5198°N, 114.897°W, alt. approx. 165 m, on mossy soil in boreal, calcareous woodland roadside under Betula sp. and Salix sp., 7 Sep 2018, H. J. Beker, L. Davies ( HJB18101 ) . Yukon: Railway Station, Whitehorse , 60.7214°N, 135.0505°W, alt. approx. 665 m, on soil and litter in boreal shrubland riverside under Populus tremuloides and Salix sp., 31 Aug 2018, H. J. Beker, L. Davies ( HJB17975 ) . 3rd Avenue near Wood St intersection, Whitehorse , 60.7212°N, 135.0555°W, alt. approx. 665 m, on grassy, mossy soil in boreal urban roadside under Populus sp., 1 Sep 2018, H. J. Beker, L. Davies ( HJB17981 ) . MEXICO. Chihuahua: El Ranchito , approx. 28.3387°N, 105.4076°W, alt. approx. 1150 m, on soil in montane, subtropical woodland, 18 Aug 2001, A. Kong 3782 (TLXM AK3782, HJB16773 ) . UNITED STATES. Alaska: Kantishna Roadhouse Nature Trail, Denali National Park , 63.5243°N, 150.9625°W, alt. approx. 490 m, on sandy soil in boreal, mixed but mainly coniferous woodland pathside under Alnus sp., Betula sp. and Salix sp., 18 Aug 2018, H. J. Beker, L. Davies (DENA-61424, HJB17897 ) . Texas: Jefferson County, Beaumont, residence of Penny Clark , approx. 30.0788°N, 94.1372°W, alt. approx. 0 m, in garden under Quercus fusiformis , 4 Dec 2015, D. Lewis DPL11907 ( HJB15699 ) . Wisconsin: Bark Point Road, near Bark Bay , 46.8353°N, 91.2594°W, alt. approx. 185 m, on grassy soil in coniferous garden under Picea glauca , 13 Sep 2017, L. Davies, H. J. Beker ( HJB16991 ) .

Remarks.

With the mixture of gently clavate and ventricose cystidia alongside the strongly dextrinoid basidiospores, this species belongs within Hebeloma sect. Velutipes . Within this section the combination of spores with minimum average width 7.5 µm and a distinctly loosening perispore in at least some spores, together with the absence of pleurocystidia, defines this species. The collection of H. neurophyllum from Mexico, gathered at El Ranchito in Chihuahua, matches well with other collections of this species. We are not aware of any synonyms for this species.

In terms of ITS, the most similar to H. neurophyllum were H. celatum , H. erebium and H. quercetorum , the ITS sequences of which were around 99% similar (99.2-98.6%) to those of H. neurophyllum . Hebeloma neurophyllum appears to correspond to UNITE SH1733487.08FU (99%). Intriguingly, this species hypothesis includes a number of soil sample sequences from Estonia, suggesting that either H. neurophyllum occurs in Europe, too, or that species known to occur in Europe also contain ITS copies corresponding to H. neurophyllum below the detection limit of Sanger sequencing.

Figures

Figure 11. Hebeloma neurophyllum, basidiomata A HJB 16991 B HJB 18101. Photos H. J. Beker.

Figure 12. Hebeloma neurophyllum A basidiospores and B spore ornamentation of isotype TENN-F- 037531 (HJB 1000453) x 1600 C basidiospores of HJB 17897 in Melzer's reagent x 1600 D basidium of isotype x 1000 E-F cheilocystidia of isotype x 1000 G caulocystidia of HJB 17975 x 500 H caulocystidia of HJB 16856 x 500 I epicutis hyphae and J subcutis of isotype x 500. All in KOH, except C. Scale bars: 5 µm (A-F); 10 µm (G-J). Photos H. J. Beker.