Hebeloma hygrophilum Poumarat & Corriol; Beker, Eberhardt, & Vesterholt, Fungi Europ. (Alassio) 14: 138, 2016.

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 hygrophilum Poumarat & Corriol; Beker, Eberhardt, & Vesterholt, Fungi Europ. (Alassio) 14: 138, 2016. Fig. 14

Macroscopic description.

Cap 0.6-3.0 cm in diameter, convex, occasionally umbonate, margin smooth, tacky when moist, not hygrophanous, uniformly colored or bicolored, at center red brown, dark brick, at margin clay-buff, sometimes with whitish fibrils, remains of universal veil variably present, partial veil present. Lamellae at first whitish or pale orange brown, becoming pale cocoa brown, attachment adnate to emarginate, maximum depth not recorded, number of lamellae {L} 23-32; droplets absent, white fimbriate edge usually present, but weak. Stem 2.0-4.3(-5.0) × 0.1-0.45(-0.7) cm, at first whitish, becoming bright orange brown to dirty brown, darker brown towards the base, cylindrical, stem Q (7.1-)10.1-25.8(-35), fibrillose, pruinose to floccose at apex. Context firm, stem interior stuffed, stem flesh discoloring from base. Smell raphanoid, sometimes weakly. Taste mild, raphanoid, later bitter. Spore deposit not recorded.

Microscopic description.

Spores shape amygdaloid, fusoid or limoniform, papillate, on ave. 11-13 × 6.0-7.0 µm, ave. Q = 1.7-2.0, brown, guttulate, sometimes weakly, weakly to distinctly ornamented ((O1) O2 (O3)), perispore not or somewhat loosening, (P0P1), distinctly to rather strongly dextrinoid (D2D3). Basidia 27-32 × 7-9 µm, ave. Q = 3.2-4.2, mostly four-spored. Cheilocystidia lageniform or ventricose, occasionally cylindrical, occasionally with characteristic apical or median wall thickening, geniculate or septate (sometimes clamped), 42-64 × 4.5-5.5 (apex) × 4-5 (middle) × 7-11.5 µm, ratios A/M = 0.89-1.24, A/B = 0.36-0.71, B/M = 1.57-2.52. Epicutis an ixocutis, thickness up to 100-130 µm (measured from exsiccata), maximum hyphae width up to 6-7 µm, ixocutis hyphae sometimes encrusted, trama elements beneath subcutis ellipsoid, sausage-shaped, sometimes cylindrical up to 20 µm wide. Caulocystidia cylindrical to ventricose, multi-septate up to 90 µm long.

Collections examined.

S-Greenland: E of Tasiusaq, 61.15°N, 45.60°W, 20 Aug 1993, E. Rald (ER 93.519, C-F-105494), 10 m, in meadow. S of Tasiusaq, 61.13°N, 45.62°W, 23 Aug 1993, E. Rald (ER 93.425, C-F-104549), 0 m. Paamiut, Taartoq/ Mørke Fiord, 62.01°N, 49.26°W, 29 Aug 1998, T. Borgen (TB98.234, C-F-103511), 5 m, with Salix glauca in copse. Narsarsuaq, north of Tasiusaq, 60.199186°N, 44.80696°W, 15 Aug 2019, T. Borgen (TB19.052, C-F-137115), 100 m, with Salix glauca in moss on streamside. W-Greenland: Kangerlussuaq, east of Ravneklippen, 67.01°N, 50.66°W, 24 Aug 2016, S.A. Elborne (SAE-2016.168-GR, C-F-106746), 120 m, with Salix glauca along lakeside copse. Kangerlussuaq, Hassells Fjeld, Kløftsøerne, 67.01°N, 50.71°W, 28 Aug 2018, H. Knudsen (HK18.390A, C-F-111118), 300 m, with Salix glauca in bog. Kangerlussuaq, Kløftsøerne, 67°N, 50.71°W, 20 Aug 2016, S.A. Elborne (SAE-2016.105-GR, C-F-106741), 300 m, with Betula nana and Bistorta vivipara along lakeside. Kangerlussuaq, Kløftsøerne, 67.03°N, 50.68°W, 20 Aug 2016, S.A. Elborne (SAE-2016.116-GR, C-F-106742), 300 m, with Salix glauca in copse. Kangerlussuaq, Kløftsøerne, 67.03°N, 50.67°W, 10 Aug 2016, H. Knudsen (HK16.064, C-F-104093), 500 m, in bog. Kangerlussuaq, Kløftsøerne, 67.01°N, 50.71°W, 28 Aug 2018, T. Borgen (TB18.236, C-F-112528), 300 m, with Salix glauca in copse. Kangerlussuaq, N slope towards Lake Ferguson, 66.95°N, 50.72°W, 29 Aug 2018, S.A. Elborne (SAE-2018.429-GR, C-F-115622), 548 m, with Salix arctophila along lakeside. Sisimiut, camping area north of town, 66.94°N, 53.67°W, 20 Aug 2000, S.A. Elborne (SAE-2000.148-GR, C-F-108600), 0 m, with Salix arctophila in bog. Sisimiut, near airport, 66.95°N, 53.67°W, 14 Aug 2016, S.A. Elborne (SAE-2016.005-GR, C-F-106735), 10 m, with Salix sp. in bog. Sisimiut, north of Alanngorsuaq, 66.95°N, 53.55°W, 15 Aug 2016, S.A. Elborne (SAE-2016.022-GR, C-F-106736), 30 m, with Salix sp. in bog. In valley S of Sisimiut behind the dump, 66.93°N, 53.67°W, 18 Aug 2016, H. Knudsen (HK16.195, C-F-108446), 25 m.

Distribution.

Found a number of times in southwestern Greenland. Recently described from subalpine areas in the Pyrenees (France) and known from scattered lowland and montane localities in much of Europe. The northernmost locality is from the Boreal zone in Finland (Rovaniemi) at 66.50°N ( Beker et al. 2016), which corresponds well in altitude with Kangerlussuaq and Sisimiut (67°N), but in Greenland these areas are Low Arctic. Hebeloma hygrophilum was recently recorded from alpine North America (Rocky Mountains, Cripps et al. 2019). Circumpolar, arctic-alpine, boreal zone.

Habitat and ecology.

Fifteen collections, ten with Salix glauca , S. arctophila or unknown Salix . One collection with Betula nana . Most collections grew in moist habitats often among Sphagnum or the moss Paludella squarrosa (Hedw.) Brid. The same type of boggy localities with Salix planifolia were reported by Cripps et al. (2019) in the Rocky Mountains and by Beker et al. (2016) from Europe, where Salix aurita , S. atrocinerea and possibly more species of Salix act as hosts.

Figures

Figure 14. Hebeloma hygrophilum A HK 16.195, photograph H. Knudsen B distribution of cited collections C spores x 1600 and D cheilocystidia x 1000 of HK 16.195 in Melzer's reagent. Scale bars: 5 µm; microphotographs H. K. J. Beker.