Hebeloma alpinum (J. Favre) Bruchet; Bull. mens. Soc. linn. Lyon 39(6(Suppl.)): 68, 1970.

Eberhardt, Ursula, Beker, Henry J., Borgen, Torbjorn, Knudsen, Henning, Schuetz, Nicole & Elborne, Steen A., 2021, A survey of Hebeloma (Hymenogastraceae) in Greenland, MycoKeys 79, pp. 17-118 : 17

Hebeloma alpinum (J. Favre) Bruchet; Bull. mens. Soc. linn. Lyon 39(6(Suppl.)): 68, 1970. Fig. 21

Macroscopic description.

Cap 1.7-7.3 cm, convex to umbonate or broadly umbonate; margin smooth, often involute, sometimes crenulate or serrate, tacky when moist, not hygrophanous, almost unicolored, occasionally bicolored, at center cream to pink buff to dark olive buff brown or yellowish brown to brownish olive or umber to sepia, clay buff or cinnamon, margin cream to pink buff or clay buff, sometimes very thin, universal veil absent, partial veil absent. Lamellae whitish, later light gray brown, then sordid brownish, number of lamellae {L} 40-72, emarginate, 0.3-0.9 cm broad, exuded drops usually visible with naked eye, but sometimes absent, with white fimbriate edge. Stem 1.5-5.0 × 0.4-1.2 cm, whitish fimbriate-pruinose in the entire length, later downwards slightly sordid ochraceous, ochre-yellowish or pale brown, base cylindric to clavate, rarely bulbous, occasionally tapering, pruinose to floccose particularly at apex, when fresh with droplets. Trama firm, stem with a stuffed interior, occasionally becoming hollow with age, not discoloring. Smell usually raphanoid, occasionally of cocoa or absent. Taste mild to weakly bitter. Spore deposit dark olive buff, brownish olive to clay buff.

Microscopic description.

Spores amygdaloid to limoniform, on ave. 9.5-15 × 5.5-8.5 µm, ave. Q = 1.4-2.2, yellow brown to brown, sometimes guttulate, papillate, sometimes very strongly, almost smooth to weakly ornamented (O1O2 (03)), perispore not or somewhat loosening (P0P1), indextrinoid to weakly dextrinoid (D0D1D2). Basidia 28-40(-45) × 8-12 µm, Q = 3-4.3, mostly four-spored. Cheilocystidia mainly clavate-stipitate or spathulate-stipitate, occasionally slenderly clavate or clavate-lageniform, occasional apically thickening, rostrate, septate or sinuate, on ave. 40-71 × 7-10 (apex) × 3.5-5 (middle) × 3.5-6 (base) µm, ratios A/M = 1.6-2.7, A/B = 1.5-2.7, B/M = 0.9-1.2. Pileipellis an ixocutis, 60-160 µm thick (measured from exsiccata), hyphae 5-6 µm broad, some encrusted; trama elements beneath subcutis cylindrical, ellipsoid, thick sausage-shaped, up to 18 µm wide. Caulocystidia similar to cheilocystidia, up to 120 µm long and 11 µm wide.

Collections examined.

S-Greenland: Paamiut, 62.01°N, 49.4°W, 18 Aug 1984, T. Borgen (TB84.148, C-F-103537), 25 m, with Salix herbacea and Salix glauca . Sermiliarsuk, Sioralik, Aasivii, 65.53°N, 48.33°W, 30 Aug 1997, T. Borgen (TB97.153a, C-F-103507), 50 m, with Betula pubescens and Salix glauca in copse. Sermiliarsuk, Sioralik, Aasivii, 65.53°N, 48.33°W, 30 Aug 1997, T. Borgen (TB97.152, C-F-103506), 50 m, with Dryas integrifolia in heathland. W-Greenland: Disko, Qeqertarsuaq, 69.24°N, 53.54°W, 5 Aug 1986, T. Borgen (TB86.141, C-F-103565), 0 m. Disko, Skarvefjeld at Qeqertarsuaq, 69.65°N, 53.32°W, 2 Aug 1986, T. Borgen (TB86.115, C-F-103458), 400 m, with Dryas integrifolia . Kangerlussuaq, airport area, 67.02°N, 50.69°W, 1 Aug 1995, T. Borgen (TB95.004, C-F-103503), 50 m, with Salix glauca and Betula nana in copse. Kangerlussuaq, Hassells Fjeld, Kløftsøerne, 67.01°N, 50.71°W, 28 Aug 2018, H. Knudsen (HK18.390D, C-F-111119), 50 m, with Salix glauca in tundra. Kangerlussuaq, near hotel, 67.02°N, 50.7°W, 7 Aug 1986, T. Borgen (TB86.153, C-F-101230), 50 m, with Salix glauca and Betula nana in tundra. Kobbefjord, NuukBasic, 64.08°N, 51.23°W, 24 Aug 2018, H. Knudsen (HK18.308, C-F-111115), 5 m, in tundra. N-Greenland: Daneborg, 0.5 km E of Airstrip, 74.2°N, 20.1°W, 29 Jul 2006, T. Borgen (TB06.034, C-F-119763), 20 m, with Dryas sp. in heathland. V. Clausen Fjord, 77.52°N, 20.66°W, 13 Aug 1990, B. Fredskild (BF 90 loc. 6, C-F-5180), 0 m. Zackenberg, Aucellabjerg, 74.47°N, 21°W, 9 Aug 2006, T. Borgen (TB06.137, C-F-119766), 160 m, with Dryas sp. and Salix arctica in heathland. Zackenberg, Aucellabjerg, 74.47°N, 21°W, 11 Aug 1999, T. Borgen (TB99.283, C-F-119808), 100 m, with Dryas sp. in heathland. Zackenberg, few 100 m west of Zackenberg River, 74.47°N, 21°W, 3 Aug 1999, T. Borgen (TB99.199, C-F-104294), 50 m, with Dryas sp. in scrubland. Zackenberg, just S of Kamelen, 74.47°N, 21°W, 27 Jul 1999, T. Borgen (TB99.115, C-F-119806), 50 m, with Dryas sp. and Salix arctica at riverside. Zackenberg, just S of Teltdammen, 74.47°N, 21°W, 20 Jul 1999, T. Borgen (TB99.027, C-F-119742), 40 m, with Dryas sp. in scrubland. Zackenberg, just S of Teltdammen, 74.3°N, 21°W, 20 Jul 1999, T. Borgen (TB99.023, C-F-119744), 40 m, with Dryas sp. and Salix sp. in scrubland. Zackenberg, just W of Kærelv, 74.47°N, 21°W, 30 Jul 1999, T. Borgen (TB99.159, C-F-119807), 30 m, with Salix arctica and Bistorta vivipara on solifluction lobe. E-Greenland: Jameson Land, Nerlerit Inaat/Constable Pynt, 70.74°N, 22.65°W, 31 Jul 2017, S.A. Elborne (SAE-2017.008-GR, C-F-106758), 10 m, with Dryas sp. and Salix sp. in tundra. Jameson Land, Nerlerit Inaat/Constable Pynt, 70.74°N, 22.67°W, 31 Jul 2017, S.A. Elborne (SAE-2017.006-GR, C-F-106757), 60 m, with Betula nana and Dryas sp. in tundra. Jameson Land, Nerlerit Inaat/Constable Pynt, around the airport, 70.74°N, 22.64°W, 31 Jul 2017, H. Knudsen (HK17.001, C-F-104889), 50 m. Jameson Land, Nerlerit Inaat/Constable Pynt, around the airport, 70.74°N, 22.64°W, 31 Jul 2017, H. Knudsen (HK17.005, C-F-104893), 50 m. Jameson Land, Nerlerit Inaat/Constable Pynt, around the airport, 70.74°N, 22.64°W, 31 Jul 2017, H. Knudsen (HK17.006, C-F-104894), 50 m. Jameson Land, Nerlerit Inaat/Constable Pynt, around the airport, 70.74°N, 22.64°W, 31 Jul 2017, H. Knudsen (HK17.007, C-F-104895), 50 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 8 Aug 2017, T. Borgen (TB17C.089, C-F-106779),40 m, with Bistorta vivipara in fenland. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 6 Aug 2017, H. Knudsen (HK17.123, C-F-105024), 40 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 7 Aug 2017, H. Knudsen (HK17.148, C-F-105050), 40 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Gåseelv, Harris Fjeld, 70.75°N, 22.68°W, 3 Aug 2017, H. Knudsen (HK17.062, C-F-104951), 95 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, H. Knudsen (HK17.049, C-F-104938), 200 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, H. Knudsen (HK17.054, C-F-104943), 200 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 10 Aug 2017, S.A. Elborne (SAE-2017.188-GR, C-F-106766), 100 m, with Salix arctica in bog. Jameson Land, Nerlerit Inaat/Constable Pynt, Mt. Harris, 70.75°N, 22.68°W, 6 Aug 2017, T. Borgen (TB17C.053, C-F-106775), 100 m, with Dryas sp. and Bistorta vivipara in heathland. Jameson Land, Nerlerit Inaat/Constable Pynt, north of Primulaelv, 70.75°N, 22.66°W, 1 Aug 2017, S.A. Elborne (SAE-2017.014-GR, C-F-106759), 10 m, with Dryas sp. Jameson Land, Nerlerit Inaat/Constable Pynt, Primulaelv, 70.74°N, 22.67°W, 13 Aug 2017, T. Borgen (TB17C.134, C-F-106784), 180 m, with Bistorta vivipara . Jameson Land, Nerlerit Inaat/Constable Pynt, Primulaelv, 70.74°N, 22.67°W, 13 Aug 2017, H. Knudsen (HK17.278, C-F-105185), 180 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Primulaelv, 70.74°N, 22.67°W, 1 Aug 2017, H. Knudsen (HK17.023, C-F-104912), 180 m, in tundra.

Distribution.

Hebeloma alpinum is one of the five most often recorded Hebeloma species in Greenland, with 36 records (almost 10%) of those considered here. This is in good accordance with Beker et al. (2016), who pointed out that this is "the most common Hebeloma species we have collected in arctic/alpine areas". It occurs all over Greenland, from Sermiliarsuk in the south (61.6°N) to Zackenberg (74.5°N) and V. Clausen Fjord (77.5°N) in the north. In Constable Pynt in East Greenland in 2017 it was the most common of all mushrooms. In Europe, it is known from the major mountain ranges (the Alps, the Pyrenees, the Tatras, the Carpathians, Black Mountains in Montenegro), from supraboreal Iceland ( Beker et al. 2016). It has been reported in North America from the Rocky Mountains (Montana, Cripps et al. 2019). Arctic-alpine, boreal and subarctic.

Habitat and ecology.

The 36 collections are all from calcareous localities. The preferred host is Dryas integrifolia but possibly also D. octopetala . When these two occur together as in NE Greenland, they often hybridize, and can be difficult to identify. Only a few collections are reported with other hosts like Salix arctica , S. herbacea , Betula pubescens , B. nana and even Bistorta vivipara . The only record from Rocky Mountains was associated with S. arctica and S. glauca . Beker et al. 2016 also have records with S. polaris , S. retusa and S. reticulata .

Notes.

The shape of the cheilocystidia clearly points to subsect. Crustuliniformia . Within this subsection, it is recognized among the other species by its habitat in arctic-alpine localities, the number of lamellae being usually between 40 and 60 and the size of the spores, on average> 11 μm long and> 6 μm wide. The squat and robust stature is a good character in the field.

Hebeloma bellotianum Berk. is a closely related or synonymous species from Bellot Island in the Canadian Arctic ( Eberhardt et al. 2015b). Unfortunately, attempts to sequence the type have been unsuccessful. It has spores on ave. 14.7 × 7.1 µm whereas the largest average measurements of 72 collections of H. alpinum is 13.7 × 7.7 µm.

Figures

Figure 21. Hebeloma alpinum A SAE- 2017.006, photograph S. A. Elborne B distribution of cited collections C spores x 1600 and D cheilocystidia x 1000 of SAE- 2017.006 in Melzer's reagent. Scale bars: 5 µm; microphotographs H. K. J. Beker.