Red Brain Fungus

Peniophora rufa

Peniophora rufa is a distinctive crust fungus that forms small, bright red, cushion-shaped structures on the dead but still bark-covered branches and trunks of aspens, including quaking aspen and big-toothed aspen. Although a microscope is probably not needed in order to identify Peniophora rufa successfully, the fungus has fascinating microscopic features, including prominent gloeocystidia.
Peniophora rufa Peniophora rufa on a small Quaking Aspen (Populus tremuloides) branch. These are dry individuals. Geotagged,Minnesota,Peniophora rufa,Populus tremuloides,Quaking Aspen,Red Brain Fungus,Spring,United States,red fungus

Appearance

Fruiting Body: Resupinate; usually growing in patches of cushion-shaped individual fruiting bodies measuring up to about 1 cm across and 2 mm high; surface waxy, wrinkled, red to orange-red when fresh (sometimes with a whitish dusting), becoming purplish with age.

Flesh: Hard; whitish to grayish.

Spore Print: White.

Microscopic Features: Spores 6-9 x 2-3 µ; smooth; cylindrical to sausage-shaped; inamyloid. Basidia 4-sterigmate. Gloeocystidia pear-shaped to clavate; 10-25 µ across. Cystidia cylindric to fusiform; scarcely projecting; 5-8 µ wide; with encrusted apices. Hyphal system monomitic. Clamp connections present.
Peniophora rufa Peniophora rufa on the trunk of a fallen Quaking Aspen (Populus tremuloides) tree. These individuals are plumped up because it had just rained a few hours earlier. Geotagged,Peniophora rufa,Populus tremuloides,Quaking Aspen,Red Brain Fungus,Spring,United States

Naming

Peniophora rufa (Fr.) Boidin, Bulletin de la Société Mycologique de France 74 (4): 443 (1959)
Thelephora rufa Fr., Elenchus Fungorum 1: 187 (1828)
Xerocarpus rufus (Fr.) P. Karst., Bidrag till Kännedom av Finlands Natur och Folk 37: 135 (1882)
Sterellum rufum (Fr.) J. Erikss., Symbolae Botanicae Upsalienses 16 (1): 120 (1958)
Tubercularia pezizoidea Schwein., Transactions of the American Philosophical Society 4 (2): 301 (1832)
Hypocrea richardsonii Vestergr., Micr. rar. sel. 404 (1867)
Peniophora rufa Peniophora rufa on the trunk of a fallen Quaking Aspen (Populus tremuloides) tree. These individuals are plumped up because it had just rained a few hours earlier. Geotagged,Peniophora rufa,Populus tremuloides,Quaking Aspen,Red Brain Fungus,Spring,United States

Distribution

http://mycoportal.org/portal/map/googlemap.php?maptype=taxa&taxon=357010&clid=81

Habitat

Saprobic and apparently sometimes pathogenic on the wood of aspens (quaking aspen and big-toothed aspen), and occasionally on the wood of other hardwoods; erupting through the still-attached bark; spring, summer, and fall; fairly widely distributed where the host trees are present (northern and montane North America).

References:

Some text fragments are auto parsed from Wikipedia.

https://www.mushroomexpert.com/peniophora_rufa.html
http://www.mycobank.org/Biolomics.aspx?Table=Mycobank&MycoBankNr_=282802
https://en.wikipedia.org/wiki/Peniophora
http://mycoportal.org/portal/taxa/index.php?taxauthid=1&taxon=357010&cl=81
http://mycoportal.org/portal/map/googlemap.php?maptype=taxa&taxon=357010&clid=81
Taxonomy
KingdomFungi
DivisionBasidiomycota
ClassAgaricomycetes
OrderRussulales
FamilyPeniophoraceae
GenusPeniophora
SpeciesPeniophora rufa