Hebeloma clavulipes Romagn.; Bull. trimest. Soc. mycol. Fr. 81(3): 326, 1965.

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 clavulipes Romagn.; Bull. trimest. Soc. mycol. Fr. 81(3): 326, 1965. Fig. 8

Macroscopic description.

Cap 1.0-4.1 cm in diameter, convex, sometimes umbonate, margin involute, rarely sulcate, tacky when moist, sometimes hygrophanous, uniformly colored or variably bicolored, at center umber to sepia (6E6, 6E7, 6F6, 6F7), margin cream to pinkish-buff to ochraceous or dark olive buff (4A2, 4A3, 5A3, 5B3, 5B5, 5C5); remains of universal veil sometimes present; partial veil present. Lamellae adnate or adnexed to emarginate, pale brown, maximum depth 3-5 mm, number of lamellae {L} 40-48, droplets usually absent, but occasionally visible with × 10 lens, white fimbriate edge usually present, but sometimes indistinctly. Stem 1.3-7.0 × 0.3-0.6 cm, 4.5-7.3(-8) cm at base, stem Q 3.3-15.5(-18), at first whitish fibrillose becoming pale brown, base cylindrical to clavate or bulbous, usually pruinose or floccose at apex. Context firm, stem inside stuffed, later hollow, stem flesh discoloring from base, sometimes weakly. Smell raphanoid, sometimes with hints of cocoa. Taste mild to bitter, usually raphanoid. Spore deposit brownish olive (5E5).

Microscopic description.

Spores amygdaloid or limoniform, occasionally appearing ovoid or fusoid, on ave. 10.5-12.5 × 6.0-6.5 µm, ave. Q 1.6-2.1, very weakly ornamented (O1O2), perispore not or somewhat loosening (P0P1), rather strongly dextrinoid (D2D3), yellow to yellow brown, ± guttulate, papillate. Basidia 23-32(-36) × 7-10 µm, ave. Q = 2.6-4.4, mostly four-spored. Cheilocystidia lageniform to ventricose, occasionally cylindrical, occasionally with a characteristic thickening, apically, basically or medially, sometimes geniculate or septate, on ave. 41-60 × 4.5-6 (apex) × 4-5.5 (middle) × 7.5-12 (base) µm, ratios A/M = 0.93-1.25, A/B = 0.45-0.76, B/M = 1.58-2.31. Epicutis an ixocutis, 125-170 µm thick (measured from exsiccata), maximum hyphae width 3.5-7 µm, sometimes encrusted, shape of trama elements beneath subcutis sausage-shaped, up to 14 µm wide. Caulocystidia similar to cheilocystidia, but usually less ventricose, up to 120 µm long.

Collections examined.

S-Greenland: Paamiut, W of the Navigation School area, 62°N, 49.67°W, 7 Sep 1990, T. Borgen (TB90.100, C-F-119760), 20 m, with Salix herbacea .

Distribution.

Only one record and apparently a very rare species in Greenland recorded only once during the 20 years when Borgen regularly collected in Paamiut. The general distribution in Europe ( Beker et al. 2016) is from the Temperate zone to southern Boreal and Subalpine zone up to 1700 m. The Greenland record is the northernmost known (62.00°N). Temperate, boreal, subarctic, and now also from Low Arctic zone.

Habitat and ecology.

Only one collection, with Salix herbacea . In Europe, the hosts are Betula , Picea and Salix ( Beker et al. 2016), but the associated Salix species are of the shrub-like kind, like S. aurita .

Figures

Figure 8. Hebeloma clavulipes A JV 02 - 517 (from Denmark), photo J. Vesterholt, reproduced by kind permission from Beker et al. (2016) B distribution of cited collections C spores x 1600 and D cheilocystidia x 1000 of TB 90.100 in Melzer's reagent. Scale bars: 5 µm; microphotographs H. K. J. Beker.