A survey of Hebeloma (Hymenogastraceae) in Greenland Author Eberhardt, Ursula https://orcid.org/0000-0003-1221-7074 Staatliches Museum fuer Naturkunde Stuttgart, Rosenstein 1, D- 70191 Stuttgart, Germany ursula.eberhardt@smns-bw.de Author Beker, Henry J. https://orcid.org/0000-0001-9620-1701 Rue Pere de Deken 19, B- 1040 Bruxelles, Belgium & Royal Holloway College, University of London, Egham, UK & Plantentuin Meise, Nieuwelaan 38, B- 1860 Meise, Belgium Author Borgen, Torbjorn https://orcid.org/0000-0003-1174-9466 Sensommervej 142, 8600 Silkeborg, Denmark Author Knudsen, Henning Hauchsvej 15, 1825 Frederiksberg, Denmark Author Schuetz, Nicole Staatliches Museum fuer Naturkunde Stuttgart, Rosenstein 1, D- 70191 Stuttgart, Germany Author Elborne, Steen A. Frederik VII's Vej 29, 3450 Allerod, Denmark text MycoKeys 2021 2021-04-19 79 17 118 http://dx.doi.org/10.3897/mycokeys.79.63363 journal article http://dx.doi.org/10.3897/mycokeys.79.63363 1314-4049-79-17 CEDC3742C169540583072E7995018533 Hebeloma pubescens Beker & U. Eberh.; Beker, Eberhardt & Vesterholt, Fungi Europ. (Alassio) 14: 173, 2016. Fig. 19 Macroscopic description. Cap 1.2-2.4 cm in diameter, convex to umbonate, sometimes papillate, margin smooth, tacky when moist, not hygrophanous, unicolored or variably bicolored, at center grayish brown to yellowish brown or umber, tomentose, usually covered, particularly at the margin, with soft hairs, at margin dark grayish buff, sometimes with remains of universal veil, partial veil present. Lamellae light brown, later slightly darker, emarginate, maximum depth 2.5-5 mm, number of lamellae {L} 25-32, droplets absent, white fimbriate edge weakly present. Stem 1.1-4.6 x 0.2-0.4 cm, whitish pale floccose in apex, downwards lengthily fibrillose, sordid brown or very pale ochraceous, cylindrical, stem Q (3.7-)4.8-8.3(-9.7), fibrillose. Context firm, stem interior stuffed, later hollow, flesh usually discoloring from base. Smell raphanoid, sometimes strongly. Taste mild. Spore deposit brownish olive. Figure 19. Hebeloma pubescens A TB99.194, photograph T. Borgen B distribution of cited collections; C spores x 1600 and D cheilocystidia x 1000 of TB99.194 in Melzer's reagent. Scale bars: 5 µm ; microphotographs H.K.J. Beker. Microscopic description. Spores ellipsoid, sometimes ovoid, pale yellow to yellow brown, guttulate, sometimes weakly, on ave. 10.0-12.0 x 6.0-6.5 µm , ave. Q = 1.5-1.8, almost smooth or weakly ornamented (O1O2), perispore not loosening (P0), indextrinoid (D0). Basidia 28-33(-37) x 8-9 µm , ave. Q = 3.1-4.4, mostly four-spored. Cheilocystidia lageniform or ventricose, occasionally with characteristic basal or median wall thickening, septate, on ave. 38-45 x 4.5-6 (apex) x 4.5-6 (middle) x 8-10.5 (base) µm , ratios A/M = 1.02-1.10, A/B = 0.51-0.73, B/M = 1.52-2.10. Epicutis an ixocutis, 90-100 µm thick (measured from exsiccata), maximum hyphae width 6 µm , sometimes encrusted, trama elements beneath subcutis isodiametric up to 15 µm wide. Caulocystidia similar to cheilocystidia but less ventricose, up to 120 µm long. Collections examined. W-Greenland : Disko, Kangaarsuk, Fortune Bay, 69.25°N , 53.54°W , 3 Aug 1986, T. Borgen (TB86.128, C-F-5089), 0 m, with Salix sp. N-Greenland : Zackenberg, W of Kaerelv , 74.5°N , 21°W , 13 Aug 1999, T. Borgen (TB99.305, C-F-119753), 50 m, with Dryas sp. in scrubland. Zackenberg, W of Zackenberg River, 74.5°N , 21°W , 5 Aug 1999, T. Borgen (TB99.194, C-F-119750), 50 m, with Dryas sp. and Salix arctica in scrubland. Distribution. Recently described from three records on Svalbard ( Beker et al. 2016 ). The Greenland records are all north of 69° and, together with the type from 78°N, establish this as one of the few agarics, which appear only to occur in the High Arctic zone. The Greenland records are new to North America and the first outside Europe. High Arctic. Habitat and ecology. Three collections, two with Dryas and one with Salix sp. The collections from Zackenberg were on rich soil. Beker et al. (2016) described it from Svalbard, where the host was Salix polaris .