Scaly Rustgill

Appearance

This mushroom is often mistaken for "Gymnopilus luteocarneus" which grows on conifers and has a smoother and darker cap. Another lookalike is "Gymnopilus penetrans" which grows in the same habitat and has minor microscopic differences.

Cap: The cap is 2.5–6 cm across, is convex, and is golden-yellow to brownish orange, darker at the center with a dry scaly surface which is often fibrillose and may have squamules. The cap margin is inrolled at first and curves outward as it matures, becoming almost plane and sometimes developing fibrillose cracks in age. The flesh is yellow to orange and delicate as compared to larger and firmer members of "Gymnopilus", such as "G. junonius".

Gills: The gills are crowded, yellow at first, turning rusty orange as the spores mature, with adnate attachments.

Microscopic Features: "Gymnopilus sapineus" spores are rusty orange to rusty brown, elliptical, rough, and 7 - 10 x 4 - 6 µm.

Stipe:: The stipe is 2.5–7 cm long and.5 cm thick. It has an equal structure or becoming thinner near the base. It is light yellow, bruising rusty brown. The stipe has an evanescent veil which often leaves fragments on the upper part of the stipe or the margin of young caps.
Taste: "Gymnopilus sapineus" sometimes tastes bitter, sometimes it does not, and it has a fungoid or sweet smell.