cf. Fuscoporia sp. (mostly synonymized as Phellinus sp.) - Orelha-de-Pau / Bracket Fungus (Murrill, 1907)

Fungi: Agaricomycetes: Agarycomycetidae: Hymenochaetales: Hymenochaetaceae

I need help confirming or correcting the genus.

There is no way for me to confirm this is a Fuscoporia sp. (sometimes synonymized as: Phellinus sp.), mainly because I forgot to take a shot of the underside to see the spores and I do not know what substract it was growing on besides being a fallen, thick trunk which seemed to be undergoing decay. This fungus belongs in the class Agaricomycetes, subclass Agarycomycetidae, order Hymenochaetales and, possibly, family Hymenochaetaceae.

There are hundreds (or thousands?) of species of bracket fungi. The determining factor for the identification of these specimens is usually done through microscopical evalutation of many traits. Hymenochaetaceae, in general, have basidiomes which provide them with a rusty color of brown and/or gold. In contact with potassium hydroxide (KOH) a chemical reaction occurs in which the part that entered in contact with the substance darkens instantly. The members of Polyporaceae, which was believed to be the correct family for this specimen for a time, in a wider aspect - such as Trametes sp. - may have many other colors which include brown, but this situation rarely occurs in all parts of the basidiome. However, a determining factor to differentiate with further reliability between Hymenochaetaceae and Polyporaceae is exactly the potassium hydroxide (KOH). Polyporaceae, in a wider aspect, do not suffer from the KOH reaction, opposing Hymenochaetaceae in that aspect. On a further note, Polyporaceae was divided in a wide range of other families. If a sky-high-risk guess would be made, we could guess the species Fuscoporia gilva.

The tubes and pores are irregular and brown, 2 to 8mm deep and terminate in small roundish red-brown pores 0.1 to 0.2mm in diameter spaced at 4 to 6 per milimeter. The spores are ellipsoidal and smooth, thin walled, hyaline, 4-6 x 3-4μm; inamyloid.

Fuscoporia are weakly parasitic saprobes that choose hardwood trees undergoing decay. They are perennial.

They might be edible, as closely related species were chewed as tobacco substitutes. However, it is advised to not do it until further reliable informations come to surface. The fungus is very hard to remove and to eat, sometimes requiring a chainsaw for the former. Even if you manage to remove one, I cannot guarantee they are not poisonous as I don't even know for sure what the family is. Take caution.

Fuscoporia's importance can be noted, among other utilities, as decomposers of hardwood. Fuscoporia gilva, for instance, decomposes wood and brackets can live on the host tree or stump for several years, adding a new growth zone and pore layer each year. (Source: https://www.dpaw.wa.gov.au/images/documents/about/science/fungus/17_2007-11_Fuscoporia_gilva_DEC_FF.pdf)

According to Catalogue of Life (17th of October, 2013), these are the species in this genus:

Fuscoporia altocedronensis
Fuscoporia bifurcata
Fuscoporia callimorpha
Fuscoporia contigua
Fuscoporia discipes
Fuscoporia ferrea
Fuscoporia ferruginosa
(syn. Phellinus ferruginosus)
Fuscoporia flavomarginata
Fuscoporia formosana
Fuscoporia longisetulosa
Fuscoporia punctata
Fuscoporia rhabarbarina
Fuscoporia senex
Fuscoporia setifera
Fuscoporia torulosa
Fuscoporia undulata
Fuscoporia wahlbergii
Fuscoporia yunnanensis

According to NCBI (17th of October, 2013), these are the species in this genus:

Fuscoporia callimorpha
Fuscoporia cinchonensis
Fuscoporia contigua
Fuscoporia discipes
Fuscoporia ferrea
Fuscoporia ferruginosa
Fuscoporia formosana
Fuscoporia gilva
Fuscoporia montana
Fuscoporia palmicola
Fuscoporia rufitincta
Fuscoporia senex
Fuscoporia torulosa
Fuscoporia viticola
Fuscoporia wahlbergii

In 1886 the genus Phellinus was circumscribed by the French mycologist Lucien Quélet. It was implicated that they were the strongest fungi of this kind. The genus Fuscoporia was established in 2007 by the American mycologist William Alphonso Murrill (1869 - 1957). Fuscoporia comes from Latin, with the adjective "fusca" meaning dark brown, reference to the dark brown surface of this Polypore.

Identified by Felipe Bittencourt.

Sources:

https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?lin=s&p=has_linkout&id=175855

http://www.catalogueoflife.org/col/search/scientific/genus/Fuscoporia/match/1

https://fr.wikipedia.org/wiki/Fuscoporia

https://www.first-nature.com/fungi/fuscoporia-torulosa.php

https://bie.ala.org.au/species/NZOR-4-46730

https://en.wikipedia.org/wiki/Fuscoporia

https://en.wikipedia.org/wiki/Fuscoporia_torulosa

Fuscoporia gilva synonimyzed as Phellinus gilvus. (https://commons.wikimedia.org/wiki/Category:Fuscoporia_gilva)