Hebeloma dunense L. Corb. & R. Heim; Mem . Soc. natn. Sci. nat. Cherbourg 40 (2): 166, 1929.

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 dunense L. Corb. & R. Heim; Mem. Soc. natn. Sci. nat. Cherbourg 40 (2): 166, 1929. Fig. 10

Macroscopic description.

Cap 1.0-7.0 cm in diameter, convex to umbonate, sometimes papillate, sometimes umbilicate, margin often involute when young, sometimes scalloped or serrate, becoming wavy or upturned with age, sometimes fibrillose along margin, tacky when moist, sometimes but not consistently hygrophanous, uniformly colored or variably bicolored, at center clay buff, dark olive buff, ochraceous or yellowish brown to brownish olive or umber or sepia to dark brick or orange brown or fuscous, at margin cream to buff or honey to pinkish buff to dark olive buff or yellowish brown to umber or sepia, sometimes with remains of universal veil, partial veil present. Lamellae light gray brown or very pale clay, later brownish clay, adnexed to adnate, usually emarginate, sometimes with decurrent tooth and occasionally decurrent, maximum depth 2.5-9 mm, number of lamellae {L} 20-48, droplets usually absent, but occasionally visible with × 10 lens, white fimbriate edge usually present, but often weak. Stem (1.0-)1.4-8.0 × (0.2-)0.3-1.2 cm, at base 0.2-1.0(-1.2) cm, stem Q = 3.5-15, base cylindrical, sometimes slenderly clavate, occasionally with sand bulb, fibrillose, pruinose or floccose at apex. Context firm, stem interior stuffed, later hollow, occasionally with superior wick, flesh usually discoloring from base, sometimes very strongly. Smell raphanoid, rarely without smell, occasionally hints of cocoa; taste mild to raphanoid to bitter. Spore deposit dark olive buff to brownish olive to umber to fuscous or sepia.

Microscopic description.

Spores mainly ellipsoid, some amygdaloid or ovoid, not papillate, 10.0-12.5 × 6.0-7.5 µm, ave. Q 1.5-1.9, very weakly ornamented (O1O2), perispore not or somewhat loosening (P0P1), indistinctly dextrinoid (D0D1), yellow through yellow brown to brown, ± guttulate. Basidia 20-33 × 7-9 µm, ave. Q = 2.8-4, mostly four-spored. Cheilocystidia usually lageniform or ventricose, sometimes cylindrical, occasionally with characteristic wall thickenings, apically, medially or basically, occasionally bifurcate, geniculate, septate (sometimes clamped), subcapitate, 34-57 × 4.5-8 (apex) × 4-7 (middle) × 7-12 (base) µm, with yellow contents, ratios A/M = 0.82-1.43, A/B = 0.42-0.89, B/M = 1.4-2.14. Epicutis an ixocutis, 25-75 µm thick (measured from exsiccata), ixocutis maximum hyphae width 4-8 µm, hyphae occasionally encrusted, shape of trama elements beneath subcutis angular, ellipsoid, isodiametric, spherical or sausage-shaped up to 20 µm wide. Caulocystidia similar to cheilocystidia, but usually more irregular and often multi-septate.

Collections examined.

S-Greenland: Kangilinnguit, 61.14°N, 48.6°W, 15 Aug 1985, T. Borgen (TB85.200, C-F-103530), 400 m, with Salix herbacea and Dryas integrifolia in snowbed. Kangilinnguit, 61.23°N, 48.10°W, 8 Aug 1984, T. Borgen (TB84.090, C-F-103535), 25 m, with Salix herbacea along streamside. Kangilinnguit, at Grønnedal Hut, 61.23°N, 48.08°W, 15 Aug 1985, T. Borgen (TB85.183, C-F-103589), 180 m. Kangilinnguit, near Grønnedal Hut, 61.23°N, 48.08°W, 15 Aug 1985, T. Borgen (TB85.186, C-F-103527), 350 m, with Salix arctophila in streamside. Narsarsuaq, 61.08°N, 45.26°W, 1 Aug 1991, T. Borgen (TB91.045, C-F-103486), 100 m, with Salix glauca . Narsarsuaq, 61.17°N, 45.41°W, 17 Aug 2015, H. Knudsen (HK15.078, C-F-8231), 60 m, with Dryas sp. along pathside. Paamiut, 62.01°N, 49.4°W, 12 Aug 1984, T. Borgen (TB84.114, C-F-103536), 10 m, with Salix glauca and Salix herbacea . W-Greenland: Kangerlussuaq, airport area, 67.02°N, 50.72°W, 10 Aug 1986, T. Borgen (TB86.177, C-F-103563), 30 m, with Salix glauca . Kangerlussuaq, near the inland ice, 67.09°N, 50.25°W, 12 Aug 2000, K. Kalamees (HK00.032, C-F-7881), 200 m, in tundra. Kangerlussuaq, Sandflugtsdalen, 67.06°N, 50.46°W, 7 Aug 2016, H. Knudsen (HK16.015, C-F-104045), 200 m, with Salix glauca . Kangerlussuaq, Sandflugtsdalen, c. 15 km E of Base, 67.04°N, 50.53°W, 7 Aug 2016, T. Borgen (TB16.076, C-F-104293), 50 m, with Salix glauca . Kangerlussuaq, Store Saltsø, 66.98°N, 50.6°W, 8 Aug 1986, T. Borgen (TB86.159, C-F-5087), 200 m, with Salix glauca . N-Greenland: Amdrup Land, 80.81°N, 17.32°W, 19 Jul 1993, B. Fredskild (s.n., C-F-7017), 225 m, with Salix arctica in tundra. Blåsø, Kronprins Christians Land, 79.62°N, 23.33°W, 4 Aug 1987, C. Bay (s.n., C-F-6994), 100 m. Prinsesse Dagmars Halvø, Knuths Fjeld, 81.58°N, 16.77°W, 6 Aug 1986, C. Bay (s.n., C-F-4216), 15 m. Zackenberg, at the S bank of Kærelv, 74.5°N, 21°W, 27 Jul 1999, T. Borgen (TB99.114, C-F-119746), 50 m, with Dryas sp. and Salix arctica in scrubland. Zackenberg, in the new delta, 74.5°N, 21°W, 22 Aug 1999, T. Borgen (TB99.411, C-F-119748), 20 m, with Salix arctica in scrubland. Zackenberg, just N of Gadekæret, 74.5°N, 21°W, 5 Aug 1999, T. Borgen (TB99.219, C-F-119752), 20 m, with Dryas sp. and Salix arctica in scrubland. Zackenberg, S of E part of airstrip, 74.5°N, 21°W, 12 Aug 2006, T. Borgen (TB06.159, C-F-119774), 30 m, with Salix arctica in snowbed. Zackenberg, Zackenberg River, 74.5°N, 21°W, 23 Aug 2006, T. Borgen (TB06.263, C-F-119776), 20 m, with Salix arctica in riverbed. E-Greenland: Jameson Land, Constable Pynt, camp N of Katedralen, S of Ugleelv, 70.9°N, 22.92°W, 25 Jul 1989, J.H. Petersen (JHP 89.259, C-F-2561), 170 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 12 Aug 2017, T. Borgen (TB17C.118, C-F-106782), 40 m, with Bistorta vivipara and Salix arctica . Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76 22.65°W, 4 Aug 2017, T. Borgen (TB17C.037, C-F-106773), 40 m, with Salix sp. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 12 Aug 2017, H. Knudsen (HK17.265B, C-F-105171), 40 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 7 Aug 2017, H. Knudsen (HK17.147, C-F-105049), 40 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 12 Aug 2017, H. Knudsen (HK17.265A, C-F-105170), 40 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.76°N, 22.65°W, 6 Aug 2017, H. Knudsen (HK17.127, C-F-105028), 40 m. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.77°N, 22.67°W, 5 Aug 2017, S.A. Elborne (SAE-2017.103-GR, C-F-106761), 40 m, with Arctostaphylos alpina . Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv valley, 70.77°N, 22.73°W, 11 Aug 2017, S.A. Elborne (SAE-2017.219-GR, C-F-106769), 40 m, with Salix arctica at riverside. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv, Harris fjeld, 70.75°N, 22.68°W, 31 Jul 2017, T. Borgen (TB17C.006, C-F-106770), 100 m, with Dryas sp. in heathland. Jameson Land, Nerlerit Inaat/Constable Pynt, delta of Gåseelv, Harris fjeld, 70.75°N, 22.68°W, 3 Aug 2017, H. Knudsen (HK17.070, C-F-1049599, 100 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Gåseelv valley, north side, 70.76°N, 22.69°W, 4 Aug 2017, H. Knudsen (HK17.088, C-F-104984), 160 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 10 Aug 2017, T. Borgen (TB17C.094, C-F-106780), 200 m, with Salix arctica in snowbed. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, T. Borgen (TB17C.030, C-F-106772), 200 m, with Salix arctica . Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, H. Knudsen (HK17.043, C-F-104932), 200 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, H. Knudsen (HK17.045, C-F-104934), 200 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, H. Knudsen (HK17.052, C-F-104941), 200 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.7°N, 22.68°W, 2 Aug 2017, H. Knudsen (HK17.056, C-F-104945), 200 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Hareelv, 70.71°N, 22.68°W, 10 Aug 2017, S.A. Elborne (SAE-2017.186-GR, C-F-106765), 200 m, with Salix arctica along streamside. Jameson Land, Nerlerit Inaat/Constable Pynt, middle of Hareelv valley, N side, 70.71°N, 22.73°W, 10 Aug 2017, H. Knudsen (HK17.203, C-F-105108), 320 m. Jameson Land, Nerlerit Inaat/Constable Pynt, Primulaelv, 70.74°N, 22.67°W, 1 Aug 2017, T. Borgen (TB17C.010, C-F-106771), 180 m, with Salix arctica and Bistorta vivipara . Jameson Land, Nerlerit Inaat/Constable Pynt, Primulaelv, 70.74°N, 22.67°W, 13 Aug 2017, H. Knudsen (HK17.282, C-F-105189), 180 m.

Distribution.

Hebeloma dunense is a common and widespread Hebeloma distributed throughout Mediterranean, Temperate, Boreal, Arctic and Alpine areas. It has been recorded in arctic and alpine areas of North America, Europe and Asia (Russia) ( Beker et al. 2016). It has one of the most northern records for a Hebeloma at 81.58° in Greenland ( Beker et al. 2016). It appears to be one of the most common and widespread of all Hebeloma species in arctic or alpine regions. Circumpolar, Temperate, Boreal, Subarctic and Arctic-Alpine.

Habitat and ecology.

Forty-two collections and one of the five most often collected species in Greenland with 11% of the collections. Most are with Salix arctica (10), S. glauca (6), S. herbacea (2), S. arctophila (1) or unspecified Salix in more or less calcareous habitats. The collection from Paamiut was from a man-made area, in this otherwise acid soil locality. Four collections were recorded with Dryas integrifolia and D. octopetala and one with Arctostaphylos alpina (L.) Spreng., although it is possible that some Salix was present. Arctostaphylos alpina is known as a likely mycorrhizal partner for Hebeloma , and has been recorded as the only possible mycorrhizal partner on several occasions (see for example Grilli et al. 2020). In the Rocky Mountains, Hebeloma dunense was recorded as mycorrhizal with S. arctica , S. planifolia and S. reticulata ( Cripps et al. 2019). Beker et al. (2016) found the same pattern for hosts; practically all collections were connected to Salix or Populus ( Salicaceae ), and a few with Dryas in arctic areas. In Beker et al. (2018), reporting on collections from Svalbard, H. dunense was recorded with Salix 91% of the time, with Dryas 16%, with Bistorta 7% (note that more than one possible host was often recorded).

Figures

Figure 10. Hebeloma dunense A SAE- 2017.103, photograph S. A. Elborne B distribution of cited collections C spores x 1600 and D cheilocystidia x 1000 of SAE- 2017.103 in Melzer's reagent. Scale bars: 5 µm; microphotographs H. K. J. Beker.