Hebeloma helodes J. Favre; Beitr. Kryptfl. Schweiz 10(3): 214, 1948.

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 helodes J. Favre; Beitr. Kryptfl. Schweiz 10(3): 214, 1948. Fig. 26

Macroscopic description.

Cap 1.3-3.8 cm in diameter, convex or sometimes weakly umbonate becoming umbilicate with age, margin usually involute at least when young, tacky when moist, not hygrophanous, mostly uniformly colored or variably bicolored, at center light ochraceous to yellowish to yellowish-brown or pale reddish brown and at margin whitish to pale cream, sometimes with remains of universal veil. Lamellae initially whitish later persistently cream, attachment emarginate, occasionally adnate, maximum depth 3-4.5 mm, number of lamellae {L} 33-54, droplets present and visible at least with × 10 lens, white fimbriate edge present. Stem 1.5-6.5 × 2.0-7.0 {median} × (2-)2.9-6.5(-7) {base} cm, whitish tomentose flocculose in the entire length, cylindrical to clavate, stem Q (3.3-)4.7-20, floccose. Context firm, stem interior stuffed, later becoming hollow, stem flesh not discoloring from base but with some weak discoloration with age. Smell raphanoid. Taste mild, raphanoid. Spore deposit dark olive buff to brownish olive.

Microscopic description.

Spores amygdaloid, on ave. 9.0-11.0 × 5.0-6.0 µm, ave. Q = 1.6-2.0, yellow to pale brown, usually guttulate, weakly to distinctly ornamented (O2O3), perispore somewhat to distinctly loosening ((P0) P1P2), indextrinoid to indistinctly dextrinoid, rarely distinctly dextrinoid (D0D1 (D2)). Basidia 22-27(-30) × 7-9 µm, ave. Q = 2.8-4.2, mostly four-spored. Cheilocystidia clavate-stipitate to capitate stipitate, occasionally more clavate-lageniform, often with characteristic apical or less frequently median wall thickening, occasionally septate, on ave. 44-63 × 8.5-11.5 (apex) × 4-5 (middle) × 3.5-5.5 (base) µm, ratios A/M = 1.90-2.86, A/B = 2.02-3.38, B/M = 0.77-1.17. Epicutis an ixocutis, 100-135 µm thick (measured from exsiccata), maximum hyphae width 5-6 µm, sometimes encrusted, trama elements beneath subcutis sausage-shaped up to 15 µm wide. Caulocystidia similar to cheilocystidia, but short, up to 11 µm wide at apex.

Collections examined.

S-Greenland: Kangilinnguit, 61.14°N, 48.6°W, 10 Aug 1985, T. Borgen (TB85.072, C-F-103460), 25 m, with Alnus alnobetulae in copse. Kangilinnguit, 61.14°N, 48.6°W, 11 Aug 1985, T. Borgen (TB85.090, C-F-103476), 25 m, with Alnus alnobetulae in copse. Kangilinnguit, 61.23°N, 48.10°W, 10 Aug 1985, T. Borgen (TB85.065, C-F-103525), 25 m, with Salix glauca in heathland. Narsaq, 60.91°N, 46.05°W, 3 Aug 1993, E. Rald (ER 93.153, C-F-104317), 20 m, with Salix glauca in scrubland. Paamiut, 62.01°N, 49.4°W, 29 Aug 1988, T. Borgen (TB88.114, C-F-4003), 50 m, in scrubland.

Distribution.

Only found in a few localities in southern Greenland. Generally distributed in warm and cold temperate Europe with a few records from subarctic Norway and Finland and missing in southern Europe. The Greenland records fit well with the European records, the records from southern Greenland (Paamiut, 62.01) being the northernmost hitherto found.

Habitat and ecology.

Five collections from heath- and scrubland recorded with Salix glauca and Alnus alnobetulae . Beker et al. (2016) suspect association with various deciduous tree families.

Figures

Figure 26. Hebeloma helodes A TB 88.114, photograph T. Borgen B distribution of cited collections C spores x 1600 and D cheilocystidia x 1000 of TB 88.114 in Melzer's reagent. Scale bars: 5 µm; microphotographs H. K. J. Beker.