Hebeloma paludicola (Photo: S. Poumarat)

Taxonomy

Types: UNITED STATES: New York: Lake Placid, Adirondack Mountains (approx. 44.2795°N, 73.9799°W, alt. approx. 550 m a.s.l.) in mixed woodland bog, 3 Dec. 1912, E.L. Murrill, W.A. Murrill (776) (Holotype. herbarium acc. no. NY 814885, HJB1000292).

Heterotypic synonyms:

• Hebeloma hygrophilum Poumarat & Corriol, Hebeloma (Fr.) P. Kumm.: 138 (2016)
• Hebeloma marginatulum var. proximum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 132 (1983)
• Hebeloma oregonense A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 149 (1983)
• Hebeloma subumbrinum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 120 (1983)

• arrow_drop_downarrow_drop_upEtymology
  From paludicola (Latin), meaning ‘a dweller in marshes’, emphasizing the habitat.

• arrow_drop_downarrow_drop_upDiagnosis
  Pileus small, thin, convex to expanded, gregarious, 1-2 cm. broad; surface viscid, smooth, glabrous, grayish-rosy-isabelline, bay on the disk in mature specimens and over most of the surface in young stages, margin entire, concolorous; lamellae sinuate, ventricose, subdistant, pallid to clay-colored; spores ovoid, smooth, melleous, tapering toward the apex, obliquely apiculate at the base, 9-10 X 6 μ; stipe long, slender, equal, white, whitish-fibrillose from the remains of the slight, evanescent veil, much twisted in dried specimens, 5-6 cm. long, 3-4 mm. thick.

Description

Description of Hebeloma paludicola based on 51 collections

• arrow_drop_downarrow_drop_upMacroscopic description
  Pileus: (6) 13–28 (35) mm diameter; shape convex, rarely applanate, umbonate or strongly umbonate; characters often remains of universal veil; margin characters often smooth, occasionally fibrillose or sulcate; viscosity tacky when moist; colour variation usually two color, rarely unicolour; colour at centre occasionally brownish olive or sepia, rarely umber, orange-brown, dark fawn, yellowish brown, clay-buff or dark brick.

  Lamellae: attachment often adnate, occasionally emarginate, rarely decurrent tooth; maximum depth 3–6 mm; number of complete lamellae 23–36; presence of tears absent; white fimbriate edge often present, occasionally weak, rarely absent.

  Cortina presence: yes.

  Stipe: (20) 28–56 (60) x 1–4 (7) {median} x 1–4 (7) {basal} mm; stipe Q 6.7–35.0; base shape cylindrical, rarely clavate; floccosity often fibrillose, occasionally pruinose at apex or floccose at apex, rarely pruinose; rooting no; thick rhizoids at base usually absent, rarely present;

  Context: Texture firm; stipe interior often hollow, occasionally stuffed; stipe flesh discolouring often yes, occasionally no, rarely very strongly; slenderness measure 11.3–66.8; smell often raphanoid, occasionally weakly raphanoid, rarely strongly raphanoid or fruit; taste often raphanoid or mild, occasionally bitter, rarely strongly raphanoid or weakly raphanoid where recorded.

  Spore deposit colour: Not recorded.

  Exsiccata characters: occasionally pileus blackening or stipe blackening.

• arrow_drop_downarrow_drop_upMicroscopic description
  Spores: shape amygdaloid, often limoniform, rarely fusoid or ovoid; colour in microscope occasionally brown, grey yellow or yellow brown, rarely brown yellow; guttules variable occasionally weak. papilla usually yes, rarely no; Spore Code: (O1) O2; P0 P1; D2 D3.

  Basidia: 22–35 (39) x 6–10 μm; ave. Q 3.1–4.2; spore arrangement 4 spored;

  Cheilocystidia: main shape lageniform, usually ventricose, rarely cylindrical, pyriform, clavate or clavate-lageniform or clavate-ventricose; special features observed often septa, occasionally geniculate, many collapsed in exsiccata or clamped septa, rarely median thickening, apical thickening, basal thickening, rostrate, sparse, yellow contents or tapering; cheilocystidia ratios: A/M = 0.89–1.24; A/B = 0.36–0.71; B/M = 1.54–2.52.

  Pleurocystidia: none seen.

  Ixocutis: epicutis thickness (measured from exsiccata) up to 130 μm; ixocutis hyphae width up to 7 μm; ixocutis hyphae encrustation yes; shape of trama elements beneath subcutis ellipsoid, often thickly sausage-shaped, occasionally cylindrical up to 20 μm wide.

  Caulocystidia: Similar to cheilocystidia but larger, up to 100 μm.

• arrow_drop_downarrow_drop_upSpore measurements

• arrow_drop_downarrow_drop_upCheilocystidia measurements

• arrow_drop_downarrow_drop_upHabitat and distribution
  Where only one possible associate was recorded, the most commonly recorded associate was Salix (91.7%) but Betula (4.2%) and Picea (4.2%) were also recorded. In these cases the most commonly recorded family was Salicaceae (95.7%). We have additional records where Pinus (10.8%), Alnus (8.1%), Abies (2.7%) and Pseudotsuga (2.7%) were recorded as possible associates, but in these cases a number of possible associates were mentioned. Overall the most commonly recorded families are Salicaceae (86.5%), Betulaceae (24.3%) and Pinaceae (21.6%) The growth habit of our collections was often scattered and occasionally gregarious or solitary.

  According to our current data, the species is found on multiple continents with collections found in Northern America (58.0%), Europe (34.0%) and Temperate Asia (8.0%). On these continents, collections has been found in the WWF biomes The World Wildlife Fund (WWF) have divided the world into 867 terrestrial ecoregions. The ecoregion here is estimated by mapping from the GPS coordinates of the collection using data made available by Dinerstein et al (2017). Use this webtool to explore the ecoregions visually or see a full list of current ecoregions on Wikipedia. tundra (28.0%), temperate broadleaf & mixed forests (24.0%), temperate conifer forests (24.0%) and boreal forests/taiga (12.0%), specifically including the ecoregions: Kalaallit Nunaat Arctic steppe (22.0%) and Colorado Rockies forests (12.0%). From collector information, it appears collections have been found in the 1.1 Forest – Boreal (26.1%), 4.1 Grassland – Tundra (21.7%), 5.10 Wetlands (inland) – Tundra wetlands (inc. pools and temporary waters from snowmelt) (15.2%) and 5.3 Wetlands (inland) – Shrub dominated wetlands (10.9%) IUCN habitats We map from the collector's description of the habitat to the International Union for Conservation of Nature (IUCN)'s definition using a standardised set of rules. Please see this page for a full list of IUCN habitats..

  Within Northern America we have records from Subarctic America (Greenland and Northwest Territories), Northwestern U.S.A. (Colorado, Oregon, Washington and Montana), Eastern Canada (Quebec) and Northeastern U.S.A. (New York).

  Within Europe we have records from the North (Finland, England, Denmark, Sweden and Norway), the Southwest (France and Spain), Eastern Europe (Estonia) and the Centre (Germany). Specimens have been collected from 41.8°N to 70.9°N.

  Within Temperate Asia we have records from Siberia (Krasnoyarsk) and Eastern Asia (Japan).

• arrow_drop_downarrow_drop_upCommentary
  With the presence of a veil, amygdaloid spores and the ventricose to lageniform cheilocystidia this species belongs within Hebeloma sect. Hebeloma. Within this section, and given the habitat, among known species, this taxon belongs to the group including, H. hygrophilum, H. nigellum, H. monticola and H. clavulipes. The last two can be ruled out, on account of their larger number of full-length lamellae, which would be regarded as close rather than subdistant. The separation between Hebeloma hygrophilum and H. nigellum may be made on spore width; the average spore width for this collection (6.5 µm) would make this H. hygrophilum, which is already know to be present in northern America, and indeed from the northeast. Further, it is known from marshy ground. As discussed in Beker et al. (2016): “Almost all of our records also mention mossy, wet or boggy ground and a number of them mention the presence of Sphagnum”. Unfortunately, no molecular data was generated from the holotype. However, there appears little doubt that this collection does represent H. hygrophilum. The name H. paludicola has priority and should therefore be considered a current name. Hesler in his unpublished manuscript of the North American Species of Hebeloma (1977) suggested the presence of pleurocystidia, albeit very sparse; this study found no evidence of pleurocystidia. It is possible that this is a mixed collection but the state of the material, which is a number of tiny fragments, makes it difficult to be certain or to try and separate the material. There exist three further later synonyms of H. paludicola. These are H. marginatulum var. proximum, H. oregonense and H. subumbrinum, all published in the same book by Smith et al. (1983). An ITS sequence exists for H. oregonense but the material for the other two taxa was collected during 1978-1980 and as mentioned in Eberhardt et al. (2022), from material collected by Smith in that period, it has proven extremely difficult to amplify DNA

Geographic distribution

Phenology

• arrow_drop_downarrow_drop_upAdditional cited collections

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