Gymnopilus luteus

December 12, 2018

This large saprobic mushroom is a pleasant sight growing from rotting logs in the latter days of summer during walks through hardwood forests.

Figure 1: a) A picture showing G. luteus growing on a well decayed log in a hardwood forest. b) The underside of G. luteus revealing gill spacing and a rusty-brown partial veil. c) This picture shows the partial veil just beginning to separate from the pileus.

Gymnopilus luteus (Peck) Hesler

Phylum: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Cortinariaceae
Genus: Gymnopilus
Species: luteus
Authority: (Peck) Hesler
Collection #: PLP847_2018_217
Locale: Eaton Rapids, MI

This large saprobic mushroom is a pleasant sight growing from rotting logs in the latter days of summer during walks through hardwood forests. The light yellow to brown caps contrast well with their environment and can make for some spectacular opportunities for a nice picture, and a picture might really be about the best way to enjoy these mushrooms. Should you decide to bring these home, the first thing you will notice is their robust ability to produce dark brown spores which will quickly coat everything nearby, so be prepared to clean up a mess if you choose not to heed this advice.

Some of the key identifying characteristics of this mushroom are its brown spores, growing on dead wood, gills attached to the stem, and a brown ring zone near the top of the stipe. This mushroom often grows gregariously but is also found growing as a lone individual. Picking this mushroom may also reveal slight blue colored bruising along the stipe or pileus. Inexperienced mycologists may confuse this mushroom with Armillaria species or even the deadly mushroom, Galerina marginata. However, the strongly bitter taste of G. luteus should ward off any ideas of eating this mushroom before considering it as an option.

Sources:

Jewell, K., & Volk, T. (2005, April). Tom Volk’s Fungus of the Month for April 2005. Retrieved from Tom Volk’s Fungus of the month.
Kuo, M. (n.d.). Gymnopilus luteus. Retrieved from MushroomExpert.Com.
Kuo, M., & Methven, A. S. (2014). Gymnopilus luteus. In M. Kuo, & A. S. Methven, Mushrooms of the Midwest (p. 187). Urbana, Chicago, Springfield, Illinois: Univerity of Illinois Press.