Birch Mazegill, Multicolor Gill Polypore Trametes betulina
This shelf-like, fan-shaped mushroom, found on dead hardwood, is notable for its hairy, concentric bands and its unusual true gills on the underside.
Appearance
- Shelf-like to fan-shaped (2-10 cm. wide)
- Without a stipe (stem)
- Upper surface is hairy, with concentric bands of cream, pale-buff, yellow-brown, or grayish-brown
- Lower surface has white true gills
- Spore print white
- Grows scattered to clustered in overlapping shelves
ID Tips
- Can be confused with turkey-tail (T. versicolor) and conifer mazegill (Gloeophyllum sepiarium)
At Edgewood
- See iNaturalist for observations in Edgewood
About
- Basidiomycetes – a major lineage of fungi that usually produce spores within basidia (club-like structures)
- Found from early to late winter
- Saprotrophic – grows on dead hardwood (e.g. oaks), occasionally on conifers
- Edibility (San Mateo County Parks prohibits removal of any natural material)
- Inedible; too tough
- Unless you are an expert, do not pick and consume wild mushrooms
Fun Facts
- Gilled polypore belongs to the Polypore family of fungi (Polyporaceae), whose members usually have vertical pores on the underside of their caps
- As nature always has exceptions, this species has true gills instead!
- The Polypore family of fungi (Polyporaceae) are typically saprotrophic
- Identifying the tree they are growing on can help determine the specific species
Learn More
Kuo, M. Oct. 2022. The polypores. MushroomExpert.Com
Roehl, T. 2017, Jul. 14. #013: Characteristics of division Basidiomycota. Fungus Fact List. Fungus Fact Friday.
Roehl, T. 2017, Jul. 7. #030: Mushroom morphology: Polypores. Fungus Fact List. Fungus Fact Friday.
References
Desjardin, D.E., M.G. Wood, and F.A. Stevens. 2016. California Mushrooms: The Comprehensive Identification Guide. Timber Press, Portland, Oregon.
Kuo, M. 2007, Mar. 4. Lenzites betulinus. MushroomExpert.Com.
Wood, M., and F. Stevens. 2024. Trametes betulina. The Fungi of California. MykoWeb.