About Gymnopilus penetrans (Fr.) Murrill
Scientific name: Gymnopilus penetrans (Fr.) Murrill
Description: The cap measures 2–8 cm (3⁄4–3+1⁄8 in) across, with a shape ranging from convex to flat. Its color is golden-yellow to brownish orange, darker at the center. It has a dry, scaly surface that is often fibrillose and may have squamules. The cap margin is inrolled when young, curves outward as the mushroom matures, becomes almost completely flat, and sometimes develops fibrillose cracks as it ages. The flesh is yellow to orange, and more delicate than the flesh of larger, firmer Gymnopilus species such as G. junonius. The gills are crowded, start yellow, and turn rusty orange as spores mature; they have an adnate attachment to the stipe. The spores are rusty orange to rusty brown, elliptical, rough, and measure 7–10 x 4–6 μm. The stipe is 3–7 cm (1+1⁄8–2+3⁄4 in) long and 0.5–1 cm thick. It can be equal in width along its length, or become thinner near the base. It is light yellow, and bruises rusty brown when damaged. The stipe has an evanescent veil that often leaves fragments on the upper section of the stipe or on the margin of young caps. This species sometimes has a bitter taste, and has a mild, fungoid or sweet smell. It is nonpoisonous, but is considered inedible. It does not stain blue, and does not contain the hallucinogen psilocybin.
Habitat and distribution: Gymnopilus penetrans grows on rotting wood under conifer trees across North America. It is generally found from June to September across most of the continent, and from September to February on the West Coast.