Hebeloma circinans (Photo: J. Vesterholt)

Taxonomy

Basionym:
Hylophila circinans Quél. ., Compt. Rend. Assoc. Franç Avancem Sci 16 (2): 587 (1888) ["1887"]

Types: Quélet, Compt. Rend. Assoc. Franç Avancem Sci 16 (2): 103 (1888) ["1887"] pl XXl 4, lectotype (icon) designated by Beker et al., Hebeloma (Fr.) P. Kumm.: (2016) page 437 (MBT203424) FRANCE: Doubs, Les Verrieres (46.6316°N, 6.1639°E, alt. approx. 1245 m a.s.l.) on calcareous, herbaceous soil in mixed, subalpine woodland under Picea sp., 27 Aug. 2007, G. Moyne (Epitype. herbarium acc. no. BR 5020184117610, HJB12063). Epitype designated by Beker et al., Hebeloma (Fr.) P. Kumm.: (2016) page 437 (MBT203425).

Homotypic synonyms:

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

• arrow_drop_downarrow_drop_upEtymology
  From circinans– making rings, to emphasise the fairy rings of this mushroom, under Picea, that Quélet found.

• arrow_drop_downarrow_drop_upOriginal diagnosis
  Stipe grêle, fibrocharnu, blanchâtre, avec des fibrilles frisées ou des flocons retroussés, subbulbeux. Peridium campanulé convexe (0m, 02), lubrifié, ochracé bistre, avec une bordure enroulée, pubescente et blanche. Chair épaisse au centre, inodore, sapide blanche. Lamellae serrées, sinuées, crème, puis rouillées, avec l’arête crénelée et blanche. Spores pruniforme oblongue (0 mm, 011–12). Été.-En cercles sous les epicéas des pâturages montagneux du Jura. Il est affine à sacchariolens.

• arrow_drop_downarrow_drop_upEnglish translation
  Stipe slender, fibrous-fleshy, whitish with curved fibrils or adpressed flocks, subbulbous. Pileus campanulate convex, 2 cm, viscid, brown-ochre, with involute white pubescent margin. Context thick at centre, without smell and taste, white. Lamellae crowded, sinuate, cream-coloured then reddish brown with crenulate, white edge. Spores prune-shaped oblong, 11–12 μm. In summer in circles under Picea in the mountain meadows of the Jura. It is close to H. sacchariolens.

Description

Description of Hebeloma circinans based on 29 collections

• arrow_drop_downarrow_drop_upMacroscopic description
  Pileus: (12) 18–35 (50) mm diameter; shape often convex, occasionally strongly umbonate, broadly umbonate or applanate; characters occasionally squamulose; margin characters often smooth or involute; viscosity tacky when moist; colour variation unicolour; colour at centre occasionally clay-buff, pinkish buff, dark pinkish buff or orange-brown.

  Lamellae: attachment usually emarginate, occasionally adnate or adnexed; maximum depth up to 2 mm; number of complete lamellae 48–65; presence of tears usually absent, rarely visible with x10 lens; white fimbriate edge occasionally present, absent or weak.

  Cortina presence: no.

  Stipe: (18) 35–56 (80) x (3) 5–7 (9) {median} x (5) 6–9 (13) {basal} mm; stipe Q 4.5–13.3; base shape clavate, occasionally cylindrical, rarely tapering; floccosity occasionally fibrillose, floccose, floccose at apex, weakly floccose, pruinose or pruinose at apex; rooting variable often weak; thick rhizoids at base absent;

  Context: Texture firm; stipe interior often hollow or stuffed; stipe flesh discolouring variable occasionally weak; slenderness measure 6.4–24.8; smell occasionally fruit, tea or odourless; taste often bitter, weakly bitter or mild where recorded.

  Spore deposit colour: Not recorded.

  Exsiccata characters: often hard, occasionally pileus blackening, rarely shiny or stipe blackening.

• arrow_drop_downarrow_drop_upMicroscopic description
  Spores: shape amygdaloid, occasionally limoniform, rarely fusoid; colour in microscope yellow brown; guttules yes. papilla variable occasionally weak; Spore Code: O2 (O3); P0 P1 (P2); D2 D3.

  Basidia: (18) 20–30 x (4) 5–7 (8) μm; ave. Q 3.6–4.4; spore arrangement 4 spored;

  Cheilocystidia: main shape cylindrical, occasionally gently clavate, rarely clavate or clavate-stipitate; special features observed occasionally septa, irregular, bifurcate, clamped septa, branching, mucronate or short, rarely apical thickening or many collapsed in exsiccata; cheilocystidia ratios: A/M = 0.99–1.23; A/B = 0.99–1.26; B/M = 0.84–1.17.

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

  Ixocutis: epicutis thickness (measured from exsiccata) up to 100 μm; ixocutis hyphae width up to 5 μm; ixocutis hyphae encrustation variable; shape of trama elements beneath subcutis ellipsoid or thickly sausage-shaped, often thinly sausage-shaped or spherical, occasionally angular, circular or cylindrical up to 20 μm wide.

  Caulocystidia: Similar to cheilocystidia but larger, up to 80 μm.

• arrow_drop_downarrow_drop_upSpore measurements

• arrow_drop_downarrow_drop_upCheilocystidia measurements

• arrow_drop_downarrow_drop_upHabitat and distribution
  Hebeloma circinans's preferred habitat appears to be boreal woodland. Where only one possible associate was recorded, the most commonly recorded associate was Picea (68.8%) but Pinus (25.0%) and Betula (6.2%) were also recorded. In these cases the most commonly recorded families were Pinaceae (94.4%) and Betulaceae (5.6%). We have additional records where Fagus (9.1%) and Abies (4.5%) were recorded as possible associates, but in these cases a number of possible associates were mentioned. Overall the most commonly recorded families are Pinaceae (95.5%), Betulaceae (13.6%) and Fagaceae (9.1%) The growth habit of our collections was often gregarious or scattered.

  According to our current collections, the species is predominantly found in Europe (92.9%) but also found in Temperate Asia (7.1%). 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. boreal forests/taiga (40.0%), temperate broadleaf & mixed forests (32.0%) and temperate conifer forests (16.0%), specifically including the ecoregions: Scandinavian and Russian taiga (40.0%), Sarmatic mixed forests (24.0%) and Alps conifer and mixed forests (12.0%). From collector information, it appears collections have been found only in the 1.1 Forest – Boreal IUCN habitat 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 Europe we have records from the North (Norway, Sweden and Finland), the Southwest (France and Italy), the Centre (Germany), Eastern Europe (Estonia) and the Southeast (Italy). Specimens have been collected from 46.2°N to 70.6°N.

  Within Temperate Asia all our records are from China (Sichuan and Xizang).

• arrow_drop_downarrow_drop_upMolecular results
  Hebeloma circinans receives full bootstrap support in all phylogenetic results, whether single locus or five-locus. All loci apart from Tef1a support the inclusion of H. circinans in H. sect. Scabrispora. The species is rather distinct olecularly and it is one of the Hebeloma species that can be identified by ITS data without problems. We are not aware of any ITS sequence from outside Europe that is likely to belong to this species.

• arrow_drop_downarrow_drop_upCommentary
  Hebeloma circinans, without annulus and with its tendency to root together with its short, mainly cylindrical cheilocystidia, is clearly a member of H. sect. Scabrispora. However, when there is no obvious rooting it may be difficult, at least microscopically, o separate this taxon from some members of H. sect. Naviculospora. Within the group of taxa with primarily cylindrical cheilocystidia, H. circinans may be distinguished by the narrow spores (at most 5.6 μm), weakly ornamented and usually with perispore at most somewhat loosening in a few spores, together with the number of full length lamellae (L), being at most 65. Also of note are the two consistent field characters of the pileus colour, being pinkish buff to clay-buff and the smell which, in every case we have collected this species, is of black tea (although sometimes also described as fruity). The smell is never raphanoid. Quélet described this species as growing in fairy rings under Picea in the Jura mountains of France. The epitype we have selected is from this region of France. This sub-alpine, subarctic species is rarely recorded. We suspect that in the field, the pale coloured pileus means it is often confused with H. laterinum. However, although the stipe of H. circinans may occasionally discolour, this discolouration is never to the same extent as the discolouration of the stipe of H. laterinum and the spores of this latter species are significantly more ornamented.

Geographic distribution

Phenology

• arrow_drop_downarrow_drop_upAdditional cited collections

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