Hebeloma aurantioumbrinum Beker, Vesterh. & U. Eberh.; Eberhardt, Beker & Vesterholt, Persoonia 35: 116, 2015.

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 aurantioumbrinum Beker, Vesterh. & U. Eberh.; Eberhardt, Beker & Vesterholt, Persoonia 35: 116, 2015. Fig. 24

Macroscopic description.

Cap 0.8-3.6 cm in diameter, umbonate or campanulate, sometimes slightly tomentose or adpressed subtomentose, at high magnification, margin smooth, tacky when moist, not generally hygrophanous, but often with hygrophanous spots, uniformly colored or variably bicolored, at center yellow brown to cinnamon to umber, but with orange elements, at margin pinkish buff to clay buff, usually very thin, without traces of any veil. Lamellae initially whitish then becoming darker and brown with maturity, emarginate, maximum depth 2 mm, number of lamellae {L} 26-42, droplets present and visible, white fimbriate edge present. Stem 1.0-4.0 × 0.15-0.5 cm, whitish lengthily fibrillose on whitish-pale ground, then sordid buff or yellowish, cylindrical, occasionally clavate, stem Q (4.7-)5.5-7, pruinose, particularly at apex. Context firm, stem interior stuffed, flesh not discoloring from base. Smell raphanoid, sometimes weakly. Taste mild or slightly bitter. Spore deposit clay buff.

Microscopic description.

Spores amygdaloid, not or weakly papillate, on ave. 10.0-12.0 × 6.0-7.0 µm, ave. Q = 1.6-1.9, pale brown to yellow-brown to brown, guttulate, almost smooth to weakly ornamented (O1O2 (O3)), perispore not or somewhat loosening (P0P1), indistinctly to weakly dextrinoid (D1D2). Basidia 28-38(-43) × 7-9(-11) µm, ave. Q = 3.2-4.4, mostly four-spored. Cheilocystidia clavate-stipitate, occasionally spathulate-stipitate or clavate-lageniform, occasionally characteristically with a median wall thickening, geniculate or septate, on ave. 45-61 × 7-8.5 (apex) × 4-5 (middle) × 4.5-5.5 (base) µm, with yellow contents, ratios A/M = 1.61-1.95, A/B = 1.62-1.98, B/M = 0.97-1.18. Epicutis an ixocutis, up to 70 µm thick (measured from exsiccata), maximum hyphae width 6 µm, sometimes encrusted, trama elements beneath subcutis ellipsoid up to 6 µm wide. Caulocystidia similar to cheilocystidia, up to 75 µm long.

Collections examined.

S-Greenland: Kangilineq/ Kvaneøen, 61.95°N, 49.47°W, 25 Aug 1990, T. Borgen (TB90.057, C-F-103482), 40 m. Kangilinnguit, bottom of Laksebund, 61.25°N, 48.08°W, 21 Aug 2018, H. Knudsen (HK18.296, C-F-111114), 100 m, in tundra. North of Tasiusaq, across the fjord from Narsarsuaq, 61.17°N, 45.61°W, 31 Jul 1993, E. Rald (ER 93.091, C-F-104321), 150 m, in Sphagnum at the lakeside. Nugarssuk, 60.26°N, 44.76°W, 9 Aug 1993, E. Rald (ER 93.262, C-F-104315), 0 m. Paamiut, 62.01°N, 49.4°W, 23 Aug 1985, T. Borgen (TB85.239, C-F-103459), 90 m, with Salix herbacea and Salix arctophila in bog. Paamiut, 62.01°N, 49.4°W, 5 Aug 1993, T. Borgen (TB93.070, C-F-103502), 10 m. Paamiut, 62.01°N, 49.4°W, 1 Sep 1990, T. Borgen (TB90.072, C-F-103484), 10 m, with Salix glauca and Bistorta vivipara . Paamiut, 62.01°N, 49.4°W, 17 Aug 1990, T. Borgen (TB90.041, C-F-103481), 10 m, with Salix glauca . Paamiut, 62.01°N, 49.4°W, 19 Aug 1985, T. Borgen (TB85.217, C-F-103526), 10 m, with Salix herbacea in snowbed. Paamiut, 62.01°N, 49.4°W, 31 Aug 1986, T. Borgen (TB86.277B, C-F-137117), 10 m, with Salix sp. Paamiut, 62.01°N, 49.4°W, 19 Aug 1984, T. Borgen (TB84.150, C-F-119792), 15 m, with Salix arctophila and Bistorta vivipara in fenland. Paamiut, 62.01°N, 49.4°W, 15 Aug 1984, T. Borgen (TB84.132, C-F-103461), 15 m, with Salix herbacea in snowbed. Paamiut, 62.01°N, 49.67°W, 12 Aug 1984, T. Borgen (TB84.112, C-F-119737), 20 m, with Salix sp. Paamiut, 62.01°N, 49.4°W, 16 Aug 1984, T. Borgen (TB84.135, C-F-103462), 10 m, with Salix arctophila , Bistorta vivipara in fenland. Paamiut, 62°N, 49.67°W, 26 Jul 1985, D. Boertmann (DB 85-17, C-F-119784), 25 m, with Salix sp. in bog. Paamiut, 62°N, 49.67°W, 26 Jul 1985, D. Boertmann (DB 85-28, C-F-119785), 25 m, with Salix sp. in bog. Paamiut, Avigaat, 62.23°N, 49.83°W, 22 Sep 1990, T. Borgen (TB90.133, C-F-103485), 60 m, with Salix herbacea and Bistorta vivipara . Paamiut, Navigation School area, 62.01°N, 49.4°W, 17 Aug 1990, T. Borgen (TB90.039, C-F-103546), 10 m, with Salix herbacea and Bistorta vivipara . Paamiut, Navigation School area, 62.01°N, 49.4°W, 13 Aug 1990, T. Borgen (TB90.029, C-F-103545), 10 m, with Salix herbacea . Paamiut, Navigation School area, 62.01°N, 49.4°W, 12 Aug 1990, T. Borgen (TB90.012, C-F-103547), 10 m, with Salix herbacea . Paamiut, Navigation School area, 62.01°N, 49.4°W, 12 Aug 1990, T. Borgen (TB90.011, C-F-103548), 10 m, with Salix herbacea . Paamiut, Telesletten, 62.01°N, 49.4°W, 23 Aug 1986, T. Borgen (TB86.251, C-F-103570), 10 m. W-Greenland: Kangerlussuaq, Lake Ferguson, Tasersuatsiaq, 66.96°N, 50.70°W, 22 Aug 2016, S.A. Elborne (SAE-2016.146-GR, C-F-106745), 350 m, with Salix glauca in streambed. Kangerlussuaq, NE facing slopes along Lake Ferguson, 66.99°N, 50.61°W, 12 Aug 2016, H. Knudsen (HK16.089, C-F-104118), 300 m. Nuuk, 64.19°N, 51.67°W, 14 Aug 1987, S.A. Elborne (SAE-1987.113-GR, C-F-119789), 300 m, with Salix herbacea in snowbed. Nuuk, airport area, 64.19°N, 51.67°W, 5 Aug 1987, H. Knudsen (HK87.004, C-F-119790), 100 m. Nuuk, Lille Malene, 64.19°N, 51.67°W, 17 Aug 1987, H. Knudsen (HK87.218, C-F-119788), 100 m. N-Greenland: Qaanaaq, 77.47°N, 69.18°W, 8 Aug 1988, S.A. Elborne (SAE-1988.149-GR, C-F-1461), 50 m. Danmarkshavn, Mørkefjord Station, 76.93°N, 20.32°W, 7 Aug 1984, B. Lauritsen (BL s.n., C-F-3637), 10 m. Danmarkshavn, Mørkefjord Station, 76.93°N, 20.32°W, 26 Jul 1982, B. Lauritsen (BL s. n., C-F-119797), 10 m. Zackenberg, Gadekæret, 74.5°N, 21°W, 21 Jul 1999, T. Borgen (TB99.044, C-F-119751), 40 m, with Salix arctica and Bistorta vivipara in scrubland. Zackenberg, Teltdammen, 74.5°N, 21°W, 5 Aug 2006, T. Borgen (TB06.091, C-F-119741), 30 m, with Salix arctica in scrubland. Zackenberg, Teltdammen, 74.5°N, 21°W, 5 Aug 2006, T. Borgen (TB06.091, C-F-119781), 30 m, with Salix arctica in scrubland. Zackenberg, Ulvehøj, 74.47°N, 21°W, 11 Aug 2006, T. Borgen (TB06.150, C-F-119768), 40 m, with Salix arctica in snowbed. Zackenberg, Østkæret, 74.47°N, 21°W, 22 Aug 2006, T. Borgen (TB06.259, C-F-119771), 40 m, with Salix arctica in fenland. E-Greenland: Jameson Land, Constable Pynt, beginning of Lollandselv, 70.92°N, 23.18°W, 31 Jul 1989, S.A. Elborne (SAE-89.430, C-F-2424), 500 m, with Salix arctica on riverside. Jameson Land, Constable Pynt, camp at ‘Vindelv’, river wnw of pt.330, 71°N, 23.47°W, 30 Jul 1989, H. Knudsen (HK89.366, C-F-2309), 230 m, with Salix arctica . Jameson Land, Constable Pynt, delta of Jyllandselv, 70.68°N, 24.06°W, 28 Jul 1988, D. Boertmann (DB GR 88-22, C-F-119787), 0 m. Jameson Land, Constable Pynt, Gåseelv, 70.77°N, 22.7°W, 18 Jul 1989, S.A. Elborne (SAE-89.121, C-F-2327), 80 m, with Salix arctica on lakeside. Lower east Skeldal, Kong Oscars Fjord, 72.27°N, 24.28°W, 17 Aug 1962, T.T. Elkington (s.n., C-F-6992), 150 m, with Cassiope in tundra and heathland. Lower east Skeldal, Kong Oscars Fjord, 72.27°N, 24.28°W, 17 Aug 1962, T.T. Elkington (s.n., C-F-6993), 150 m, with Cassiope , tundra and heathland.

Distribution.

Hebeloma aurantioumbrinum is one of the five most commonly recorded Hebeloma in Greenland with 10.5% of the records considered here. It is common and widely distributed in arctic areas in Europe ( Beker et al. 2016). From alpine areas, it is known from North America ( Cripps et al. 2019), but not from the well-investigated alpine mountains in Europe ( Beker et al. 2016). Circumpolar, arctic-alpine.

Habitat and ecology.

Forty collections with a number of hosts recorded, including: Salix herbacea (11), S. arctica (5), S. glauca (5), S. arctophila (3), Salix sp. (5), Bistorta vivipara (8, but never as the only possible associate). The localities are also scattered between wet and dry places, but favoring wet areas with S. herbacea , without having a preference for specific soil conditions. Beker et al. (2016) also found a preference for Salix , including S. polaris .

Figures

Figure 24. Hebeloma aurantioumbrinum A SAE- 2016.146, photograph S. A. Elborne B distribution of cited collections C spores x 1600 and D cheilocystidia x 1000 of SAE- 2016.146 in Melzer's reagent. Scale bars: 5 µm; microphotographs H. K. J. Beker.