Hebeloma caulocystidiosum (Photo: C.L. Ovrebo)

Taxonomy

Types: UNITED STATES: Tennessee: Van Buren, Sparta, Fall Creek Falls St. Pk. (approx. 35.6617°N, 85.3444°W, alt. approx. 500 m a.s.l.), 10 Oct. 1972, L.R. Hesler (Holotype. herbarium acc. no. TENN-F-037533, HJB1000337).

Heterotypic synonyms:

• Hebeloma crustuliniforme var. brevipes Murrill, Lloydia 9: 327 (1946)

• arrow_drop_downarrow_drop_upEtymology

• arrow_drop_downarrow_drop_upOriginal diagnosis
  Pileus 3-4.5 cm latus, roseo-bubalinus, hic illic fuscescens, glaber, viscidus. Contextus albus; odor raphanoideus, gustus amaro-raphanoideus. Lamellae emarginatae, avellaneae, deinde subfuscae, confertae, angustiores. Stipes 1-2.5 cm longus, 5-10 mm crassus, albus, nitidus, apice pruinosus, siccus. Sporae 10-12(-14) x 5-5.5(-6) μm, fusiformes, minute rugulosae. Pleurocystidia desunt; cheilocystidia 33-78 x 3-5 μm, filamentosa. Pilei trama intertextum. Hypodermium cellulare. (Figs. 2E-H.)

• arrow_drop_downarrow_drop_upEnglish translation
  Pileus 3-4.5 cm broad, pinkish-buff, here and there pale brown, glabrous, viscid. Context white; smell raphanoid, taste bitter-raphanoid. Lamellae emarginate, hazel brown, then light brown, crowded, somewhat narrow. Stipe 1-2.5 cm long, 5-10 mm thick, white, shining, pruinose at the apex, dry. Spores 10-12 (-14) x 5-5.5 (-6) μm, fusiform, minutely roughened. Pleurocystidia none; cheilocystidia 33-78 x 3-5 μm, filamentous. Pileus trama intertwined. Hypoderm cellular. (Figs. 2E-H.)

Description

Description of Hebeloma caulocystidiosum based on 11 collections

• arrow_drop_downarrow_drop_upMacroscopic description
  Pileus: (30) 37–51 (65) mm diameter; shape convex; characters Not recorded; margin characters reflexed or wavy; viscosity tacky when moist; colour variation often unicolour, occasionally two color; colour at centre occasionally pinkish buff, yellowish brown, cinnamon or dark fawn.

  Lamellae: attachment often decurrent tooth or emarginate, occasionally adnate or adnexed; maximum depth up to 6 mm; number of complete lamellae 64–80; presence of tears absent; white fimbriate edge often present, occasionally weak.

  Cortina presence: no.

  Stipe: (10) 20–37 (50) x (5) 7–12 (15) {median} x (5) 8–16 (19) {basal} mm; stipe Q 2.0–4.5; base shape often bulbous or cylindrical, occasionally clavate; floccosity often pruinose at apex or velute, occasionally fibrillose or floccose at apex; rooting no; thick rhizoids at base variable;

  Context: Texture firm; stipe interior hollow, occasionally stuffed; stipe flesh discolouring no; slenderness measure 1.0–3.9; smell often raphanoid, occasionally earthy or odourless; taste often bitter, occasionally none or raphanoid where recorded.

  Spore deposit colour: Not recorded.

  Exsiccata characters: dark.

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

  Basidia: 21–34 (36) x 6–8 (9) μm; ave. Q 3.0–4.2; spore arrangement 4 spored;

  Cheilocystidia: main shape gently clavate, usually ventricose, often cylindrical or clavate-lageniform or clavate-ventricose, occasionally lageniform; special features observed occasionally septa, geniculate, many collapsed in exsiccata or bifurcate; cheilocystidia ratios: A/M = 1.21–1.45; A/B = 0.84–1.36; B/M = 1.02–1.58.

  Pleurocystidia: none seen.

  Ixocutis: epicutis thickness (measured from exsiccata) up to 110 μm; ixocutis hyphae width up to 6 μm; ixocutis hyphae encrustation yes; shape of trama elements beneath subcutis cylindrical, occasionally thickly sausage-shaped up to 16 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 caulocystidiosum's preferred habitat appears to be deciduous woodland, sloping woodland, shaded lawn or lawn with soil or grassy soil. Where only one possible associate was recorded, the most commonly recorded associate was Quercus (85.7%) but Pinus (14.3%) were also recorded. In these cases the most commonly recorded families were Fagaceae (85.7%) and Pinaceae (14.3%). Overall the most commonly recorded families are Fagaceae (85.7%) and Pinaceae (14.3%) The growth habit of our collections was often scattered and occasionally caespitose, gregarious or solitary.

  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 broadleaf & mixed forests (50.0%) and temperate grasslands, savannas & shrublands (50.0%), specifically including the ecoregions: Southeast US conifer savannas (37.5%), Appalachian mixed mesophytic forests (25.0%), Upper Midwest US forest-savanna transition (12.5%), Eastern Great Lakes lowland forests (12.5%) and Cross-Timbers savanna-woodland (12.5%). From collector information, it appears collections have been found in the 1.4 Forest – Temperate (66.7%) and 14.5 Urban Areas (33.3%) 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 Southeastern U.S.A. (Florida, Alabama and Tennessee), North-central U.S.A. (Minnesota), Northeastern U.S.A. (New York), North-central U.s.a (Oklahoma) and South-central U.S.A. (Louisiana).

Geographic distribution

Phenology

• arrow_drop_downarrow_drop_upAdditional cited collections

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