Phellinus fibrosus Ryvarden, Gomes-Silva & Gibertoni 2012, sp. nov.
Creators: name: Gomes-Silva, Allyne Christina
name: Ryvarden, Leif
name: Gibertoni, Tatiana Baptista
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Hymenochaetales
Hymenochaetaceae
Phellinus
Phellinus fibrosus

description: Phellinus fibrosus Ryvarden, Gomes-Silva & Gibertoni sp. nov. (Figs. 1 A–F)   
MycoBank no.: MB 564296  
 This species differs from other Phellinus species by its abundant tramal setae with a long hyphal-like base, a distinctly swollen middle part and a tapering long acute apex, and by fibrous consistency of tubes and context.   
 Type (designated here): — BRAZIL. Amazonas: Manaus, Campus do INPA, on angiosperm tree, April 1978, leg. M.A. Sousa & L.F. Coelho 396 (holotype: INPA 84261, isotype: O and URM 83725).   
 Etymology: —“Fibrosus” (Lat.) refers to the loose and fibrous tubes.   
Basidiomata perennial, reflexed resupinate with a narrow pileus in upper edge of one of the basidiomata, up to 8 cm long and 1 cm thick in the resupinate part; pileus glabrous, dull, sulcate, fulvous (12) to snuff brown (17) at the margin and becoming darker at the older parts and ultimately black and slightly indurated in the oldest part, hard and fragile as dry; pore surface umber (18) to snuff brown (17) slightly cracked in the resupinate part; pores round to angular, 7−10 per mm, invisible to the naked eye; dissepments distinctly thin; margin rounded and smooth; tubes concolorous with pore surface, indistinct by the naked eye, about 1 cm thick at resupinate part, fibrous and easily disintegrated, up to 5 mm deep and further losing its distinct structure boundary of context; context and upper part of tubes fibrous, fulvous (12) to snuff brown (17) with a black zone up to 1 mm wide between the context and the substrate. Hyphal system dimitic; generative hyphae thin walled, hyaline, simple-septate, 2−4 µm wide and difficult to find in the type specimen; skeletal hyphae yeollowish to rusty brown in KOH, thick-walled with a very narrow lumen, 3−5 µm wide; tramal setae abundant, acute with a distinct swollen middle part, tapering to a long narrow hyphal “tail” down to the simple septum from which they arised, 8−15 µm in the widened middle part, up to 90 µm in length; hymenial setae 12−24 × 5−10 µm, dark brown, thick-walled, acute ventricose, less common than tramal setae; basidia not seen in the type specimen; basidiospores subglobose to ellipsoid, pale yellow in 3% KOH, smooth, slightly thick-walled, negative in Melzer's reagent, 4−5 × 3−3.5 µm.  
 Habitat: —Found on angiosperm tree.   
 Distribution: — Phellinus fibrosus is only known from the state of Amazonas, Brazil.   
 Remarks: —This is an unique species in which the abundant tramal setae have a long hypha like base, a distinctly swollen middle part and ending with a tapering long acute apex. This together with the presence of small hymenial setae and the fibrous consistency of tubes and context make it very distinct. By using the key in Fidalgo (1968), Larsen & Cobb-Poulle (1990) and Ryvarden (2004) there is no species with the combination of characters as outlined above. Phellinus pachyphloeus (Pat.) Pat. is similar, but differs by firm to woody hard basidiomata, larger setal hyphae (850–900 × 8–35 µm), smooth hymenial setae that are straight or curved at the base and globose to ellipsoid basidiospores, 4.5−6 × 4−5.5 µm (Fidalgo 1968, Ryvarden & Johansen 1980).
description: Published as part of Gomes-Silva, Allyne Christina, Ryvarden, Leif & Gibertoni, Tatiana Baptista, 2012, Two new species of Phellinus s. l. from the Brazilian Amazonia, pp. 55-60 in Phytotaxa 67 (1) on pages 56-57, DOI: 10.11646/phytotaxa.67.1.4, http://zenodo.org/record/5065986