Boletales » Boletaceae » Neotropicomus

Neotropicomus australis

Neotropicomus australis A.C. Magnago 2022, in Magnago, et al., Mycologia 114, 607-625 (2022)

Etymology: australis (Latin), referring to the type locality in southern Brazil.

Diagnosis: Differs from Neotropicomus parvogracilis by its finely pruinose to subscabrous upper stipe, black NH4OH reaction on the pileus, and presence of cheilocystidia.

Pileus 1636 mm broad, convex to plano-convex with age; surface smooth to rugulose, slightly viscid when wet, reddish brown (OAC 636, OAC 734), lighter concolorous to pinkish brown (OAC 667) toward the margin; margin straight. Hymenophore adnate, depressed and sublamellate around the stipe, light greenish yellow (OAC 849) to yellow (OAC 856); tubes 34 mm long centrally; pores mostly 1 mm wide, angular, unchanging under pressure. Stipe 1836 × 4 7 mm, central, equal, upper half finely pruinose to subscabrous; scales reddish brown (OAC 733) over a cream (OAC 857) ground; lower half increasingly glabrous and light brown (OAC 750); basal mycelium white, downy. Context pale white (OAC 816), unchanging on exposure. Odor and taste not obtained. Macrochemical reactions: 10% NH4OH black on pileus surface and pinkish on stipe surface; 3% KOH reddish on pore surface. Basidiospores olivaceous in fresh deposit, 1214 × 45 μm (Qm = 2.58, n = 40, s = 8), subfusoid to fusoid, golden yellow in H2O, paler in 3% KOH, smooth, thin-walled, inamyloid. Basidia 2938 × 1013 μm, clavate, hyaline with many oil droplets, 4-sterigmate; sterigmata 34 μm long. Pleurocystidia scattered, 4872 × 811 μm, narrowly fusoid to ventricose with a long neck, hyaline, inamyloid. Cheilocystidia 1933 × 1013 μm, pyriform, broadly clavate or ventricose, hyaline, inamyloid. Hymenophoral trama phylloporoid, hyaline; mediostratum poorly differentiated; individual hyphae 47 μm wide; lateral stratum not gelatinizing, of densely arranged, parallel to slightly divergent hyphae, these 512 μm wide. Pileipellis a trichoderm of anticlinal, densely packed chains of subglobose cells and polymorphic terminal elements, these globose to broadly clavate, often with subacute papillate apex, 1735 × 1118 μm, hyaline, inamyloid. Pileus trama interwoven; individual hyphae 419 μm wide, hyaline. Stipitipellis a palisade of erect clusters of hyaline caulocystidia, these 1634 × 913 μm, subglobose, pyriform, clavate or fusiform. Stipe trama of compact, longitudinally oriented hyphae, these 412 μm wide. Clamp connections absent.

Index Fungorum Number:  IF836728



Figure 1. Neotropicomus australis. AG. ACM 1000, holotype. H. ACM 1152. A. Basidiospores. B. Basidia. C. Pleurocystidia.D. Cheilocystidia. E. Pileipellis terminal elements. F. Stipitipellis. GH. Basidiomata. Bars: AD = 10 μm; EF = 25 μm; GH = 10 mm.



Magnago, A. C., & Alves-Silva, G., & Henkel, T. W., & da Silveira, R. M. B. (2022). New genera, species, and combinations of Boletaceae from Brazil and Guyana. Mycologia 114, 607-625.


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The webpage Basidiomycota provides an up-to-date classification and account of all genera of the phylum Basidiomycota.


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