Hairy parchment (Stereum hirsutum) is a fungi often found in association with witch’s butter (see “Witch’s Butter” on 01-01-2016) on dead deciduous (sometimes conifer) wood from Canada to South Carolina and west to British Columbia south to California. Hairy parchment is integral to the breakdown of wood.
The fruiting body is shelf-like, bract-like or can be partially resupinate (lying flat), occurring singly, in rows, or as grouped, fused masses.
The cap is densely hairy (under a hand lens), concentrically zoned and may have a wavy margin. The coloration is variable, but usually the inner zones are reddish brown to chestnut brown with the cap margins being orange, gold or tawny. The fertile, spore-producing surface is on the underside of the cap and is smooth, lacking pores, tubes or gills. Older specimens may show a greenish tinge caused by algae.
When moist, hairy parchment is leathery and pliant, but stiff and rigid when dry. This fungus is an annual that continues to return year after year.
Hairy parchment is not know to be poisonous, but its leathery and tough nature makes it inedible.
The scientific name provides a good description of hairy parchment. The genus name derives from “ster” meaning “hard” and the species name, hirsutum, means “hairy”.
These hairy parchment fungi were growing in association with witch’s butter (Tremella mesenterica) on a dead oak log near Burney Creek in Burney Falls State Park (CA).