Hebeloma ingratum (Photo: H. J. Beker)

Taxonomy

Types: FRANCE: Haute Savoie, Montcharvet, near Saint-Bon (Savoie) (approx. 45.3967°N, 6.6856°E, alt. approx. 1750 m a.s.l.) on grassy soil in alpine meadow edge under Betula alba, Picea sp., Populus tremula and Salix cinerea, 11 Sep. 1964, G. Bruchet (Holotype. herbarium acc. no. LY BR64-24, HJB1000040).

Heterotypic synonyms:

• Hebeloma asperulatum Hesler, Kew Bulletin 31 (3): 472 (1977)

Homotypic synonyms:

• Hebelomatis ingratum (Bruchet) Locq., Flore Mycologique Vol III - Text. Cortinariales A: 146 (1979) ["1977"]

• arrow_drop_downarrow_drop_upEtymology
  From ingratus– disagreeable, presumably to emphasise the smell that Bruchet found disagreeable, peppery, strong and persistent, reminiscent of Asarum europaeum.

• arrow_drop_downarrow_drop_upOriginal diagnosis
  Cortina nulla; pileo usque ad 60 mm lato, adulto planissimo, concolore, pallidiore, toto pruinato, e cremeo velo ochraceo carneo; stipite 45–65 x 6–8 mm, subbulboso, albido, sub lamellis dense pulverulento-punctato, dein tenuiter floccoso; lamellis lacrymantibus, guttulis limpidis madidis; odore subingrato, gravi, persistente, Asarum europaeum L. in mentem revocante; Sporis 11–13 x 5,5–6 μm, amygdaliformibus, s.m. luteis, in massa luteolis, ornamentis humilioribus, pariete haud firma; pilis marginum longioribus, gracilibus, magis minusve f1exuosis et parum superne dilatatis. In oris pratorum, sub Populo tremula L., magis minusve aliis arboribus frondosis mixtum.

• arrow_drop_downarrow_drop_upEnglish translation
  Cortina absent; pileus up to 60 mm broad, very flat when mature, uniformly coloured, pale, entirely pruinose, surface pale cream-coloured, centre flesh-coloured ochre; stipe 45–65 × 6–8 mm, subbulbous, white, below the lamellae densely pruinose-punctate, downwards finely floccose; lamellae weeping, with clear droplets when moist; smell slightly unpleasant, heavy, persisting, reminiscent of Asarum europaeum; spores 11–13 × 5.5–6 μm, amygdaloid, yellow under microscope, with fine ornamentation; marginal hairs rather long and slender, hardly widened at apex. In the border of a meadow, under Populus tremula and in mixed deciduous-coniferous forests.

Description

Description of Hebeloma ingratum based on 112 collections

• arrow_drop_downarrow_drop_upMacroscopic description
  Pileus: (18) 24–52 (75) mm diameter; shape often convex, occasionally umbonate or strongly umbonate, rarely broadly umbonate, applanate or none; characters occasionally spotting, rarely hygrophanous or pruinose; margin characters often smooth, rarely crenulate, involute, overhanging pileus, scalloped, serrate or sulcate; viscosity tacky when moist; colour variation often two color, occasionally unicolour; colour at centre occasionally cream, ochraceous, dark pinkish buff or yellowish brown, rarely clay-pink, cinnamon, pale yellow or clay-buff.

  Lamellae: attachment usually emarginate, rarely adnate or adnexed; maximum depth 3–7 mm; number of complete lamellae 48–78; presence of tears often absent, occasionally visible with x10 lens, rarely visible with naked eye; white fimbriate edge often present, occasionally weak, rarely very strong.

  Cortina presence: no.

  Stipe: (15) 31–65 (150) x 3–7 (12) {median} x (4) 5–10 (13) {basal} mm; stipe Q 2.5–15.7; base shape often cylindrical or clavate, rarely bulbous, subbulbous or tapering; floccosity occasionally pruinose or pruinose at apex, rarely floccose, floccose at apex, weakly floccose, none or velute; rooting no; thick rhizoids at base usually absent, rarely present;

  Context: Texture firm; stipe interior often stuffed or hollow, rarely superior wick; stipe flesh discolouring variable occasionally weak; slenderness measure 3.3–25.2; smell often raphanoid, occasionally odourless, rarely weakly raphanoid, cocoa, tea or strongly raphanoid; taste occasionally bitter, mild, raphanoid or weakly bitter where recorded.

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

  Exsiccata characters: occasionally lamellae blackening, pale or stipe blackening.

• arrow_drop_downarrow_drop_upMicroscopic description
  Spores: shape amygdaloid, occasionally limoniform, rarely fusoid; colour in microscope often yellow, occasionally yellow brown, brown yellow or very pale; guttules often no, occasionally yes. papilla variable occasionally weak; Spore Code: O2 O3; P0 P1 (P2); D1 D2.

  Basidia: (19) 20–32 x 5–9 (10) μm; ave. Q 3.2–3.9; spore arrangement 4 spored;

  Cheilocystidia: main shape clavate-lageniform or clavate-ventricose, occasionally clavate-stipitate, rarely clavate, gently clavate, ventricose or lageniform; special features observed often median thickening, occasionally septa, rarely apical thickening, geniculate or many collapsed in exsiccata; cheilocystidia ratios: A/M = 1.40–2.14; A/B = 0.90–1.42; B/M = 1.39–1.75.

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

  Ixocutis: epicutis thickness (measured from exsiccata) up to 300 μm; ixocutis hyphae width up to 6 μm; ixocutis hyphae encrustation yes; shape of trama elements beneath subcutis often thickly sausage-shaped, occasionally isodiametric or oblong up to 15 μm wide.

  Caulocystidia: Similar to cheilocystidia but larger, up to 150 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 (32.0%) but Populus (16.0%), Betula (12.0%), Picea (12.0%), Pinus (12.0%), Quercus (4.0%), Fagus (4.0%), Tilia (4.0%) and Dryas (4.0%) were also recorded. In these cases the most commonly recorded families were Salicaceae (44.8%), Pinaceae (27.6%), Betulaceae (13.8%) and Fagaceae (6.9%). We have additional records where Alnus (11.8%), Abies (3.2%), Carpinus (2.1%), Tsuga (2.1%), Arctostaphylos (2.1%), Pseudotsuga (1.1%) and Larix (1.1%) were recorded as possible associates, but in these cases a number of possible associates were mentioned. Overall the most commonly recorded families are Salicaceae (67.7%), Pinaceae (59.1%), Betulaceae (39.8%), Fagaceae (10.8%) and Rosaceae (8.6%) The growth habit of our collections was often scattered, occasionally solitary and rarely gregarious or caespitose.

  According to our current data, the species is found on multiple continents with collections found in Northern America (57.5%), Europe (35.9%) and Temperate Asia (6.6%). 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 broadleaf & mixed forests (32.3%), boreal forests/taiga (31.2%) and tundra (21.9%), specifically including the ecoregions: Northern Canadian Shield taiga (10.4%) and Pacific Coastal Mountain icefields and tundra (10.4%). From collector information, it appears collections have been found in the 1.1 Forest – Boreal (32.5%), 1.4 Forest – Temperate (27.7%) and 5.11 Wetlands (inland) – Alpine wetlands (inc. temporary waters from snowmelt) (12.0%) 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 (Alaska, Northwest Territories, Yukon, Greenland and Nunavut), Eastern Canada (Quebec and Newfoundland and Labrador), Western Canada (Alberta and British Columbia), Northwestern U.S.A. (Washington), Mexico (Mexico), North-central U.S.A. (Wisconsin) and Southeastern U.S.A. (Tennessee).

  Within Europe we have records from the Centre (Belgium, Poland, Germany, Switzerland and Netherlands), the Southwest (France and Spain) and the North (Denmark, England, Finland and Norway). Specimens have been collected from 42.4°N to 69.2°N.

  Within Temperate Asia we have records from Caucasus (Adygea, Georgia and Karachay-Balkar) and China (Yunnan).

• arrow_drop_downarrow_drop_upMolecular results
  Hebeloma ingratum is paraphyletic with respect to H. fragilipes, H. pseudofragilipes and the enigmatic ICG19 in the ITS, to part of H. hiemale in MCM7 (Eberhardt et al. 2016), to singleton sequences of H. laetitiae and H. hiemale in V9 and in a very basal position within the main H. sect. Denudata clade, paraphyletic to all subclades. Hebeloma ingratum is monophyletic in Tef1a and monophyletic but split into two well supported subclades in RPB2; the amplification success we had for both of these loci was poor. In spite of that, H. ingratum does form a reasonably well supported clade in five and six-locus results. Identification by ITS via BLAST searches bears the risk of mistaking H. ingratum for H. fragilipes or H. pseudofragilipes or vice versa.

• arrow_drop_downarrow_drop_upCommentary
  Given the shape of its cheilocystidia (primarily clavate-lageniform) and the spores mainly O3 and D2, H. ingratum belongs to H. sect. Denudata, subsect. Clepsydroida. This species most likely corresponds to ICG11 of Aanen & Kuyper (1999). Within this subsection, the dextrinoidity, usually D2 (weakly but distinctly dextrinoid), places it in the group of four species with H. cavipes, H. fragilipes and H. pseudofragilipes. It is worth noting that all four of these species (along with H. hiemale) often exhibit median-thickening in the cheilocystidia wall. Also note that H. cavipes and H. pseudofragilipes often have a majority of spores D3, a character that does not seem to appear in either H. fragilipes or H. ingratum. Hebeloma ingratum usually has some distinctly brown colours in the pileus, which separates it from H. fragilipes and H. pseudofragilipes, both of which are closely allied to H. ingratum (both morphologically as well as molecularly). It can be distinguished from H. cavipes because of the shorter spores, on average less than 11 μm long (H. cavipes has spores of average length at least 11 μm long). Within H. subsect. Clepsydroida, the only species we have recorded within arctic or alpine habitats are H. ingratum and H. vaccinum. Indeed within the whole of H. sect. Denudata the only other species with the characteristic clavate-lageniform cheilocystidia (as the main cheilocystidium shape) that appears to grow in arctic or alpine areas is H. hiemale. These three species are normally quite easy to tell apart. Given that we also have records of H. ingratum from subalpine habitats, we suspect that this species has a wide range throughout Northern Europe and, possibly, also into other arctic or alpine areas of the northern hemisphere. Since Bruchet’s naming of this species it appears to have been rarely recorded. Vesterholt (2005) makes no mention of this species and indeed until recently Vesterholt considered that this taxon was probably synonymous with H. fragilipes. It is certainly very closely related with H. fragilipes and it is likely that it has often been recorded under this name.

Geographic distribution

Phenology

• arrow_drop_downarrow_drop_upAdditional cited collections

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