fungus

Inocutis dryophila is a widespread, wood-decaying fungus. It occurs in Europe, Asia, Australia, southern Africa, North America, Central America, and South America. In the United States it occurs east of the Great Plains, across the south to California, and north along the West Coast.

Inocutis dryophila is found, solitary or overlapping, almost exclusively on the trunks of living oaks (Quercus spp.), but it has been found on other hardwoods, including ash.

The fruiting body is up to 3″ (8 cm) wide. The upper surface is reddish yellow, reddish-orange, yellowish brown, brownish orange, or dark reddish-orange brown. The color is often zoned. It is finely hairy at first. As it matures, it becomes entirely hairless and clumped, and the surface becomes papery. There is no tough outer layer (cortex). The margin is wavy and sometimes lobed.

There is usually no stalk, but sometimes there is a broadly expanding stalk or base that is connected laterally or eccentrically. When present, the stalk is short, up to 13⁄16″ (3 cm) long and ¾″ (2 cm) wide, narrower at the base and expanding to the cap. It is rusty brown, and it is covered with soft hairs.

The pore surface is buff colored at first becoming dark reddish brown. There are 1 to 3 pores per millimeter. The pores are angular, thin walled, and up to ⅜″ (10 mm) deep. Their walls are thin, and their edges become deeply and irregularly cut (lacerated) with age.

The flesh, if it could be called that, consists of a hard, granular, brown and white core that is up to 3⅛″ (8 cm) thick; a fibrous, yellowish-brown tissue layer that is up to 13⁄16″ (3 cm) thick; and a tube layer that is up to 13⁄16″ (3 cm) thick. The tube layer is whitish inside at first, becoming the same color as the cap with age.

The spore print is brownish.

Fungus (Inocutis rheades) is similar but smaller. It is found on poplars, cottonwoods, and aspens (Populus spp.).

Living oaks

Sources

4, 24, 26, 29, 30, 77.

This species was formerly classified as Inonotus dryophilus. A microscopic analysis (Fiasson & Niemela, 1984) separated three European species, including this one, into a new genus Inocutis. DNA studies published in 2001 and 2002 supported the move.

I believe this is Inocutis dryophila. … My friend said we should call it ‘Orange Crumbly Muffin’.

Inonotus dryophilus, a plant pathogen
Nature's Perfection

Greg Watson
7/31/2024

Location: Great River Bluffs State Park

I believe this is Inocutis dryophila. … My friend said we should call it ‘Orange Crumbly Muffin’.