Tyromyces galactinus (Berk.) J. Lowe 1975

Spongipellis galactinus (Berk.) Pat. Tax. Hymen. 84. 1900
Polyporus galaciinus 'Qtx^. I^ond. Jour. Bot. d: 321. 1847.
? Tranieies malicola Berk. & Curt. Jour. Acad. Phila. II. 3 : 209. 1856. (Type from Pennsylvania.)
Polyporus immitis Peck, Ann. Rep. N. Y. State Mus. 35: 135. 1884. (Type from New York.)
Pileus cespitose-imbricate, soft, spongy and watery when fresh, rigid and brittle when dry, dimidiate or reniform, elongate behind, applanate or convex, much contorted on drying, 3-5X5-10X0.5-1 cm.; surface hispid or strigose-tomentose, white, azonate, smooth or slightly tuberculose, becoming isabelline on drying ; margin thin, but often obtuse, sterile, entire, discolored and inflexed when dry : context zonate, firm, fibrous-woody below, spongy above, 3-7 mm. thick ; tubes 3-5 mm. long, slender, white to isabelline, mouths minute, white, glistening, angular or slightly flexuose, 6 to a mm., edges very thin, laceratedentate, at length isabelline : spores ellipsoidal, smooth, hyaline, 3-4 X 1.5-2 /i.
Type locality : Waynesville, Ohio, on rotten trunks. Habitat : Dead or diseased. trunks of deciduous trees. Disa:RiBUTiON : Eastern Canada to Ohio.

Tyromyces galactinus is a species of poroid fungus in the family Polyporaceae. Found in North America, is a plant pathogen that causes a white rot in broad-leaved trees. The fungus was first described by Miles Joseph Berkeley in 1847. The type was collected near Waynesville, Ohio, where it was found growing on rotting trunks. Although originally placed in genus Tyromyces by Russian mycologist Appollinaris Semenovich Bondartsev in 1953, the name is invalid as it did not confirm to the rules for naming species. Josiah Lincoln Lowe transferred the fungus to Tyromyces validly in 1975.