Overview
The Hairy Curtain Crust (Stereum hirsutum), also celebrated as the False Turkey Tail, is a common, strikingly vibrant crust fungus native to deciduous woodlands worldwide. Forming undulating, overlapping tiers of leathery shelves along dead hardwood branches and oak logs, its upper surface is densely coated in coarse, velvety greyish hairs, while its margin and smooth underside glow in brilliant, radiant shades of saffron, mustard-yellow, and warm orange.
Biology and Physical Characteristics
Stereum hirsutum produces thin, tough, leathery basidiocarps that grow either flat against wood (resupinate) or curl outward into wavy, fan-shaped brackets (effused-reflexed). The upper cap surface is distinctly zoned with concentric bands of yellow, buff, and grey, covered in a thick coat of bristly, coarse hairs. Unlike polypores that feature tiny pores, the underside is completely smooth, lacking pores or gills entirely, and is colored bright golden-yellow to rich ochre.
Behavior and Ecology
Operating as a vigorous white-rot saprotroph, the Hairy Curtain Crust colonizes freshly fallen deadwood, particularly oak (Quercus), beech (Fagus), and birch, breaking down lignin to recycle essential nutrients into the forest ecosystem. It is remarkably drought-tolerant: during dry spells, its leathery brackets shrivel and curl up, rehydrating and resuming active spore release within minutes of the next rainstorm.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, Stereum hirsutum is exceptionally common across global temperate forests. In mycology, it is famous as the specialized host of the parasitic Jelly Rot fungus (Phlebia tremellosa) and Yellow Brain fungus (Tremella aurantia), which parasitize its mycelium inside decaying oak logs.
Interesting Factoid
The Hairy Curtain Crust has no pores or gills at all; unlike true bracket mushrooms that drop spores through tiny tubes, its underside is completely flat and smooth like a coat of yellow paint, releasing spores directly from its smooth surface.