Inocybaceae: Inocybe

Inocybe viscata (E. Horak) Garrido

Bibliotheca Mycol. 120: 177 (1988)

  • Astrosporina viscata E. Horak, N.Z. J. Bot. 15: 733 (1978) [1977]

PILEUS 18-60 mm diam, obtusely conical to conico-campanulate, soon expanding to plano-convex to plane, often with a low obtuse umbo that can be pronounced, margin incurved in youth, soon decurved and undulating upon expansion becoming torn or split in age; surface lubricous-viscid (not unlike species of Hebeloma), surface often with adhering particles of mud or soil; disc smooth and unbroken, radially fibrillose or rimulose towards the margin, not scaly; color somewhat complex—almost bicolorous—brown on the disc and around the center (10YR 4/3) but with a very pale brown margin (10YR 7/3), in youth brown (10YR 5/4) at center and light yellowish brown to very pale brown (10YR 6/4-7/3) towards the margin, in age the center is umber (7.5YR 4/4) with a yellowish brown (10YR 5/6) to light yellowish brown (10YR 6/4) margin, context dingy isabelline to pale brown, -6 mm thick, odor none, color not changing where cut or bruised, not confluent with the stipe. LAMELLAE adnexed, very close, c. 48-62 L with several tiers of lamellulae; pallid or Cartridge Buff (2.5Y 8/4) in youth, becoming light yellowish brown (2.5YR6/4) or light olive brown (2.5Y 4/4) to brown (10YR 5/3) in age; edges pallid and indistinctly fimbriate; ventricose, -5 mm broad. STIPE 35-80 ´ (3-) 4-10 mm at the apex, even or with a bulbous base, not marginate, more rounded bulbous 6-12 mm wide, terete to compressed; surface densely white pruinose along the upper half to two-thirds, striatulate in appearance, white fibrillose below to densely so towards the base, rather pallid throughout due to pruinose covering when young but with light yellowish brown ground color that is more pronounced in age, pale brown to brown (10YR 6/3-5/3 to 7.5YR 4/4) in age; context firm, solid, pallid to brownish particularly in age but whitish at the extreme base, no color changes observed where cut or bruised.

SPORES 6.7-8.0-9.0 (-9.5) ± 0.64 ´ 4.9-5.4-6.2 (-6.5) ± 0.40 µm (n=42/2), gibbous with 6-8 low or moderate-sized obtuse nodules, at times weakly nodulose, yellowish brown. BASIDIA 30-35 ´ 9-10 µm, 4-sterigmate, clavate, hyaline. PLEUROCYSTIDIA 49-53 ´ 13-17 µm, fusiform, utriform, or subcylindric, neck not extensive, with a basal pedicel; very thick-walled, walls up to 6.0 µm thick, hyaline or pale yellowish. CHEILOCYSTIDIA similar to pleurocystidia, mixed with narrowly clavate paracystidia. CAULOCYSTIDIA not frequent, often irregularly cylindric, at times ochraceous and collapsed, mixed with numerous cauloparacystidia, descending at least towards the center but lower part with vesture of interwoven to subgelatinous layer of smooth, hyaline hyphae, these 3-5 µm wide and similar to epicutis. PILEIPELLIS distinctly two-layered with the epicutis comprised of a thick, subgelatinous, interwoven velipellar layer of cylindric, smooth (or faintly wrinkled) hyphae, these mostly 4-7 µm wide; the subcutis is tawny is mass and composed of incrusted hyphae more regularly arranged, hyphae here wider than above, at times filled with tawny refractive substance. CLAMPS present.

HABITAT: in soil along disturbed roadsides in wet sclerophyll in Tasmania, on soil in Nothofagus forests in New Zealand, April to May in New Zealand, February to June and November in Tasmania. Putative ectomycorrhizal hosts include Nothofagus (New Zealand) and Eucalyptus (Australia).

SPECIMENS EXAMINED: AUSTRALIA: TASMANIA. In natural bushland, Truganini Reserve, Hobart, 10-Nov-2004, leg G. Gates (I97, TENN065732, HO); same as previous locality, 18-Nov-2007, leg. G. Gates (I102, TENN066121, HO) (Inocybe cf. viscata); on disturbed soil along roadside in wet sclerophyll under Eucalyptus regnans, Acacia, Pomaderris, at end of Russell Falls Track onto road, Mt. Field National Park, leg P.B. Matheny, D. Ratkowsy, 8-Jun-2009 (PBM3213, TENN065733); same locality as above buried deep in disturbed soil under Eucalyptus regnans and Pomaderris, leg. P.B. Matheny, 1-Jun-2010 (PBM3445, TENN065734).

COMMENTS: Inocybe viscata is reported here for the first time from Australia. Here we cite four collections, all from Tasmania. In New Zealand, where the species was originally described (Horak 1977), I. viscata is poorly known and represented at PDD by the type and one additional collection, the identification of which is tenuous. New records for this species from Tasmania are therefore quite significant. Inocybe viscata is a rather robust species considering other Australian taxa. The species has a conspicuous lubricous pileus when wet, but this feature may not be obvious after specimens have dried out in the field. Under the microscope, however, a rather thick, subgelatinous epicutis is easily detectable on the collections we have examined. Because of its rather viscid nature (like species of Hebeloma), dirt and debris are often stuck to the pileus in Tasmanian collections. The ITS sequence of PBM3213, collected in a wet sclerophyll forest in Tasmania, where Nothofagus was absent, differs at two base pair positions and two minor gaps from the ITS (GU23318) of the holotype (PDD27109) from New Zealand collected under Nothofagus cliffortioides (Horak 1977). Overall, the large robust size, lubricous pileus, striatulate and pruinose stipe, short cystidia, and spores with relatively few nodules are useful features that readily identify I. viscata. Collection I102 (I. cf. viscata) differs from the type at the ITS locus (only 94% similar) and seven unique substitutions at the nLSU locus. More data are needed to ascertain a circumscription for this taxon.


  • Horak E (1977) Fungi Agaricini Novaezelandiae VI. Inocybe (Fr.) Fr. and Astrosporina Schroeter. N.Z. J. Bot. 15: 713-747.