Hebeloma discomorbidum (Photo: H. J. Beker)

Taxonomy

Basionym:
Agaricus discomorbidus Peck [as "Agaricus (Naucoria) discomorbidus"], Bull. Buffalo Soc. nat. Sci. 1: 52 (1873)

Types: UNITED STATES: New York: Lewis County and Columbia County, Croghan and Copake (approx. 43.8959°N, 75.3924°W, alt. approx. 250 m a.s.l.) on soil in woodland, Sep. 1872, C.H. Peck (Lectotype. herbarium acc. no. NYS-F-001019.1, HJB1000535; Isotype. herbarium acc. no. WTU-F-039667, HJB1000557; Isotype. herbarium acc. no. NYS-F-001019.2, HJB1000562). Lectotype designated by Eberhardt et al., Mycologia 114 (2): (2022) page 354 (MBT10000884).

• arrow_drop_downarrow_drop_upType notes
  As part of this project we have had access to two parts: NYS-F-001019.1 annotated as “this specimen was loose in box labelled Croghan & Copake”; NYS-F-001019.2 annotated as “this specimen was in same packet as NYSf1019.3 (enclosed in Croghan & Copake box)”. There is no doubt that the exsiccata from both these parts represent the same collection and indeed both show the darkening of the disk which Peck clearly regarded as very important, whence the epithet. Lectotype designated was NYS-F-001019.1. No DNA sequence information obtained.

Heterotypic synonyms:

• Hebeloma clavulipes Romagn., Bull. Trimestriel Soc. Mycol. France 81 (3): 326 (1929) ["1965"]
• Hebeloma oreophilum Beker & U. Eberh., Mycologia 107 (6): 1295 (2015)
• Hebeloma candidipes Bruchet, Bull. Mens. Soc. Linn. Lyon 39, supplement 6: 125 (1970)
• Hebeloma mesophaeum var. macrosporum L. Rémy, Bulletin trimestriel de la Société Mycologique de France 80 (4): 531 (1965) ["1964"]
• Hebeloma remyi Bruchet, Bull. Mens. Soc. Linn. Lyon 39, supplement 6: 29 (1970)
• Hebeloma corrugatum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 116 (1983)
• Hebeloma felleum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 151 (1983)
• Hebeloma flaccidum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 144 (1983)
• Hebeloma fragrans A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 91 (1983)
• Hebeloma fragrans var. intermedium A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 92 (1983)
• Hebeloma fuscostipes A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 119 (1983)
• Hebeloma griseocanum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 113 (1983)
• Hebeloma hesleri A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 122 (1983)
• Hebeloma idahoense A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 143 (1983)
• Hebeloma limacinum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 103 (1983)
• Hebeloma lutescentipes A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 154 (1983)
• Hebeloma marginatulum var. fallax A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 130 (1983)
• Hebeloma obscurum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 124 (1983)
• Hebeloma occidentale A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 121 (1983)
• Hebeloma oregonense var. atrobrunneum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 150 (1983)
• Hebeloma pallescens A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 137 (1983)
• Hebeloma palustre Peck, Ann. Rep. N.Y. St. Mus. 52: 649 (1899)
• Hebeloma perfarinaceum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 153 (1983)
• Hebeloma piceicola A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 126 (1983)
• Hebeloma praecaespitosum A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 118 (1983)
• Hebeloma praelatifolium A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 157 (1983)
• Hebeloma pseudofastabile A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 127 (1983)
• Hebeloma stanleyense A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 147 (1983)
• Hebeloma subboreale A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 33 (1983)
• Hebeloma subrubescens A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 136 (1983)
• Hebeloma utahense A.H. Sm., V.S. Evenson & Mitchel, The Veiled Species of Hebeloma in the Western United States: 29 (1983)
• Hygrophorus montanus Murrill, Mycologia 3 (4): 199 (1911)

Homotypic synonyms:

• Naucoria discomorbida (Peck) Sacc., Syll. Fung. 5: 842 (1887)

• arrow_drop_downarrow_drop_upEtymology
  From disco (Latin), meaning ‘disc’ and morbidus (Latin) meaning ‘diseased’ or ‘unwholesome’.

• arrow_drop_downarrow_drop_upDiagnosis
  Pileus thin, convex or expanded, smooth, slightly viscid, reddish-brown or dull chestnut; lamellae narrow, crowded, minutely serrulate, white or pallid, then brownish; stem equal, stuffed, smooth, slightly mealy at the top, white; flesh white; spores nucleate, .0004' x .00025' [10.2 x 6.4 µm]. Plant 2'-3' high [50.8-76.2 mm], pileus 1'-1.5' broad [25.4-38.1 mm], stem l''-2'' thick [2.5-5 mm]. Ground in woods. Croghan and Copake. September and October. In the dried specimens the disk has a dark discolored appearance as if it is beginning to decay.

Description

Description of Hebeloma discomorbidum based on 141 collections

• arrow_drop_downarrow_drop_upMacroscopic description
  Pileus: (8) 15–35 (50) mm diameter; shape usually convex, occasionally umbonate, rarely weakly umbonate, strongly umbonate, applanate or broadly umbonate; characters often remains of universal veil, occasionally hygrophanous; margin characters often smooth, occasionally involute or fibrillose, rarely sulcate, reflexed, wavy or crenulate; viscosity tacky when moist; colour variation often two color, occasionally unicolour; colour at centre occasionally brownish olive, rarely sepia, umber, yellowish brown, fuscous, cinnamon, dark fawn, dark brick, brick, clay-buff, orange-brown, fawn, greyish brown, ochraceous or cream.

  Lamellae: attachment often emarginate, occasionally adnate, rarely adnexed; maximum depth 2–8 mm; number of complete lamellae 38–50; presence of tears usually absent, rarely visible with x10 lens or visible with naked eye; white fimbriate edge often present, occasionally weak, rarely absent.

  Cortina presence: yes.

  Stipe: (13) 24–69 (110) x (1) 2–6 (10) {median} x (1) 2–7 (12) {basal} mm; stipe Q 3.3–25.0; base shape usually cylindrical, occasionally clavate, rarely tapering or bulbous; floccosity often fibrillose, occasionally pruinose at apex, rarely floccose at apex, pruinose, fibrous, floccose or none; rooting no; thick rhizoids at base absent;

  Context: Texture firm; stipe interior often hollow, occasionally stuffed; stipe flesh discolouring often yes, rarely no, weak or very strongly; slenderness measure 4.2–645.3; smell often raphanoid, rarely strongly raphanoid, odourless, weakly raphanoid, earthy, cocoa or fruit; taste occasionally mild or raphanoid, rarely weakly bitter, none, strongly bitter, weakly raphanoid, bitter or strongly raphanoid where recorded.

  Spore deposit colour: often brownish olive, occasionally yellowish brown.

  Exsiccata characters: occasionally dark, rarely pileus blackening, stipe blackening or lamellae blackening.

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

  Basidia: (17) 21–36 (38) x (5) 6–10 μm; ave. Q 2.8–4.3; spore arrangement 4 spored;

  Cheilocystidia: main shape usually lageniform or ventricose, occasionally cylindrical, rarely pyriform, balloon-shaped, clavate or clavate-lageniform or clavate-ventricose; special features observed often septa, occasionally median thickening, basal thickening, geniculate or many collapsed in exsiccata, rarely apical thickening, clamped septa, sparse, thick content in neck or yellow contents; cheilocystidia ratios: A/M = 0.87–1.46; A/B = 0.42–0.81; B/M = 1.49–2.40.

  Pleurocystidia: usually none seen, rarely only close to lamella edge or seen.

  Ixocutis: epicutis thickness (measured from exsiccata) up to 170 μm; ixocutis hyphae width up to 7 μm; ixocutis hyphae encrustation often no, occasionally yes; shape of trama elements beneath subcutis often thickly sausage-shaped, occasionally thinly sausage-shaped, rarely cylindrical or polygonal up to 18 μm wide.

  Caulocystidia: Similar to cheilocystidia but larger, up to 120 μm.

• arrow_drop_downarrow_drop_upSpore measurements

• arrow_drop_downarrow_drop_upCheilocystidia measurements

• arrow_drop_downarrow_drop_upHabitat and distribution
  Hebeloma discomorbidum's preferred substrate appears to be mossy soil. Where only one possible associate was recorded, the most commonly recorded associate was Salix (60.9%) but Picea (25.0%), Betula (3.1%), Alnus (3.1%), Fagus (1.6%), Dryas (1.6%), Populus (1.6%), Tsuga (1.6%) and Pinus (1.6%) were also recorded. In these cases the most commonly recorded families were Salicaceae (51.4%), Pinaceae (41.7%) and Betulaceae (5.6%). We have additional records where Abies was recorded as a possible associate, but for these collections a number of possible associates were mentioned. Overall the most commonly recorded families are Salicaceae (57.7%), Pinaceae (38.7%) and Betulaceae (24.3%) The growth habit of our collections was often scattered, occasionally gregarious and rarely caespitose or solitary.

  According to our current data, the species is found on multiple continents with collections found in Northern America (55.4%), Europe (40.3%), Temperate Asia (3.6%) and Southern America (0.7%). 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. temperate conifer forests (44.8%), tundra (24.6%) and temperate broadleaf & mixed forests (11.2%), specifically including the ecoregions: Colorado Rockies forests (23.1%) and Kalaallit Nunaat Arctic steppe (11.2%). From collector information, it appears collections have been found in the 1.1 Forest – Boreal (31.1%), 4.1 Grassland – Tundra (25.4%), 1.4 Forest – Temperate (12.3%) and 5.11 Wetlands (inland) – Alpine wetlands (inc. temporary waters from snowmelt) (11.5%) 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 Northwestern U.S.A. (Colorado, Montana, Idaho, Oregon, Wyoming and Washington), Subarctic America (Greenland, Alaska and Northwest Territories), Northeastern U.S.A. (New York), Eastern Canada (Newfoundland and Labrador and Quebec) and Southwestern U.S.A. (Utah).

  Within Europe we have records from the North (Svalbard, Finland, Sweden, Norway, Denmark and England), the Centre (Slovakia, Germany, Poland and Czech Republic), the Southwest (France) and the Southeast (Italy). Specimens have been collected from 44.9°N to 78.3°N.

  Within Temperate Asia we have records from Siberia (Krasnoyarsk and Tyumen) and Russian Far East (Sakha).

  Within Southern America all our records are from Caribbean (Jamaica).

• arrow_drop_downarrow_drop_upCommentary
  We were unable to generate DNA sequence information from any of the available syntype or isotype material. The ventricose to lageniform cheilocystidia together with the amygdaloid to fusoid spores indicate that this belongs to Hebeloma sect. Hebeloma and, given the habitat, most likely the group of species that includes H. clavulipes, H. hygrophilum, H. monticola, and H. nigellum. The protologue mentions that the lamellae are crowded and while it is difficult to estimate the number of full-length lamellae from the exsiccata it certainly appears to exceed 40, which would rule out H. hygrophilum and H. nigellum, which normally do not have more than 36 full-length lamellae. The spore size would indicate that this is what we used to call Hebeloma clavulipes in, e.g. Eberhardt et al. (2015, 2021a), Beker et al. (2016, 2018) and Cripps et al. (2019), but it should be noted that H. palustre Peck (1899) should also be referred to the same species. In Eberhardt et al. (2022) we gave H. palustre Peck 1899 as the current name for thsi taxon. Since the publication of that paper, it has been brought to our attention by J-P. Chaumeton that according to ICBN Art. 11.4 (Turland et al. 2018) the valid name for the taxon Hebeloma palustre is actually H. discomorbidum, as this species was originally described in 1873 as Agaricus discomorbidus, which predates the publication of H. palustre which was published in 1899.

Geographic distribution

Phenology

• arrow_drop_downarrow_drop_upAdditional cited collections

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