Hebeloma australe (Photo: H. J. Beker)

Taxonomy

Types: UNITED STATES: Florida: Alachua, Gainesville, Newnan's Lake (approx. 29.6932°N, 82.219°W, alt. approx. 50 m a.s.l.) under Quercus virginiana, 28 Dec. 1942, W.A. Murrill (Holotype. herbarium acc. no. FLAS-F-21535, HJB1000321; Isotype. herbarium acc. no. TENN-F-016164, HJB1000449).

• arrow_drop_downarrow_drop_upEtymology
  From australis (Latin), meaning ‘south or southern’. Presumably Murrill saw this as a species that was more common in the south of the continent.

• arrow_drop_downarrow_drop_upOriginal diagnosis
  Pileo convexo-subexpanso, 4-5 cm. lato, glabro, subviscido, rosei-isabellino, amaro; lamellis adnexis, latis, confertis, denticulatis; sporis ovoideis, levis, pallidis, 10-12 X 5-6 μ; stipe pallido, floccoso, bulboso, 4-5 X 0.6-0.8 cm.

• arrow_drop_downarrow_drop_upEnglish translation
  Pileus convex to subapplanate, 4-5 cm. broad, glabrous, almost viscid, pinkish-Isabella, bitter; lamellae adnexed, broad, crowded, serrulate; spores ovoid, smooth, pale, 10-12 x 5-6 μ; stipe pale, floccose, bulbous, 4-5 x 0.6-0.8 cm.

Description

Description of Hebeloma australe based on 88 collections

• arrow_drop_downarrow_drop_upMacroscopic description
  Pileus: (26) 38–68 (90) mm diameter; shape often convex, occasionally applanate, umbilicate or broadly umbonate, rarely strongly umbonate; characters rarely spotting, hygrophanous or undulating; margin characters often smooth, occasionally involute or eroded, rarely reflexed or wavy; viscosity tacky when moist; colour variation often two color, occasionally unicolour; colour at centre occasionally dark brick, pale pinkish buff or fawn, rarely pale salmon, brick, dark pinkish buff, cinnamon, clay-buff, greyish buff or pale cream.

  Lamellae: attachment usually emarginate, rarely adnexed; maximum depth 4–10 mm; number of complete lamellae 71–90; presence of tears usually absent, rarely visible with x10 lens or visible with naked eye; white fimbriate edge often weak, occasionally present.

  Cortina presence: no.

  Stipe: (17) 25–46 (60) x (6) 7–14 (20) {median} x (9) 10–19 (27) {basal} mm; stipe Q 1.4–6.7; base shape often bulbous or clavate, occasionally cylindrical, rarely tapering; floccosity often floccose or pruinose at apex, rarely fibrillose, pruinose or velute; rooting usually no, rarely yes; thick rhizoids at base often absent, occasionally present;

  Context: Texture firm; stipe interior often hollow or superior wick, occasionally stuffed or basal wick; stipe flesh discolouring often yes, occasionally no or weak, rarely very strongly; slenderness measure 0.8–6.5; smell often marzipan, rarely fruit, odourless, raphanoid or sweet; taste often bitter, occasionally mild or none where recorded.

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

  Exsiccata characters: Not recorded.

• arrow_drop_downarrow_drop_upMicroscopic description
  Spores: shape amygdaloid, rarely limoniform; colour in microscope often yellow, occasionally brown yellow, yellow brown or grey yellow, rarely brown; guttules variable occasionally weak. papilla variable often weak; Spore Code: (O1) O2; P0; D2 D3.

  Basidia: (19) 22–33 (37) x (5) 6–9 (10) μm; ave. Q 3.1–4.1; spore arrangement usually 4 spored, rarely variable;

  Cheilocystidia: main shape clavate-lageniform or clavate-ventricose, occasionally ventricose or cylindrical, rarely gently clavate, lageniform, clavate-stipitate or utriform; special features observed often septa, occasionally median thickening or many collapsed in exsiccata, rarely apical thickening, basal thickening, bifurcate, irregular or yellow contents; cheilocystidia ratios: A/M = 1.21–1.94; A/B = 0.79–1.12; B/M = 1.49–1.81.

  Pleurocystidia: none seen.

  Ixocutis: epicutis thickness (measured from exsiccata) up to 150 μm; ixocutis hyphae width up to 8 μm; ixocutis hyphae encrustation usually yes, occasionally no; shape of trama elements beneath subcutis often cylindrical, isodiametric or thickly sausage-shaped, occasionally ellipsoid up to 20 μm wide.

  Caulocystidia: Similar to cheilocystidia but larger, up to 160 μm.

• arrow_drop_downarrow_drop_upSpore measurements

• arrow_drop_downarrow_drop_upCheilocystidia measurements

• arrow_drop_downarrow_drop_upHabitat and distribution
  Hebeloma australe's preferred habitat appears to be mixed woodland or pine-barrens with sandy soil. Where only one possible associate was recorded, the most commonly recorded associate was Quercus (66.7%) but Pinus (33.3%) were also recorded. In these cases the most commonly recorded families were Fagaceae (66.7%) and Pinaceae (33.3%). We have additional records where Fagus (7.8%), Betula (6.5%), Tsuga (3.9%) and Carya (1.3%) were recorded as possible associates, but in these cases a number of possible associates were mentioned. Overall the most commonly recorded families are Fagaceae (89.6%), Pinaceae (81.8%) and Betulaceae (6.5%) The growth habit of our collections was often scattered, occasionally gregarious and rarely solitary or caespitose.

  According to our current collections, the species is found only in Northern America. On the continent, 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 (50.6%), temperate broadleaf & mixed forests (23.5%) and temperate grasslands, savannas & shrublands (22.4%), specifically including the ecoregions: Atlantic coastal pine barrens (47.1%), Southeast US conifer savannas (21.2%) and Northeast US Coastal forests (11.8%). From collector information, it appears collections have been found only in the 1.4 Forest – Temperate 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 Northern America we have records from Northeastern U.S.A. (New York, Massachusetts, New Jersey, Rhode Island and Pennsylvania), Southeastern U.S.A. (Florida and Georgia) and South-central U.S.A. (Texas).

• arrow_drop_downarrow_drop_upCommentary
  With amygdaloid, weakly dextrinoid spores and the clavate-ventricose cheilocystidia, greater than 40 µm long, it may be assumed that this taxon belongs to H. subsect. Clepsydroida. The description of the color of the pileus as rosy-isabelline brings to mind H. laetitiae. However, the spores are almost smooth, a character unknown from this section and further, the bulbous base of the stipe does not fit. Hebeloma hiemale can have less ornamented spores but the pileus can hardly be described as pinkish and the stipe does not have a bulbous base. While, unfortunately, no molecular data was generated from the holotype, a partial ITS sequence was generated from the isotype and this matched the ITS sequence generated from the authentic material collected by G.F. Weber from the same site on the next day. These sequences, and the morphological data, indicate that this a species distinct from any recorded, to date, from Europe. It is also conspecific with a number of collections of a distinctive mushroom (when fresh) from the pine barrens of Long Island, New York and New Jersey. Of note is the odor of fresh material of many of these collections, which resembles the smell of marzipan. The name H. australe should be accepted as a current name. We are not aware of any synonyms of this taxon. While morphology brings to mind species from H. sect. Denudata, molecularly, H. australe does not seem to be particularly closely related to this section. Rather, it might be related to H. sect. Sacchariolentia or the core group (excluding H. islandicum) of H. sect. Naviculospora. We are currently not in a position to place H. australe in any of the existing sections with any degree of confidence but also hesitate to erect a new section for this species. Although no sequence data has been published under the name of H. australe, a UNITE species hypothesis (SH1184977.08FU) at the 3% level exists that presumably corresponds to H. australe, including only sequences from northern America.

Geographic distribution

Phenology

• arrow_drop_downarrow_drop_upAdditional cited collections

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