Yellow Fieldcap

Yellow Fieldcap © CMathews

Sunny Side Up
Bolbitius titubans

This small, yellow mushroom thrives on dung, compost, and fertilized grass year-round when adequate moisture is present.

Appearance

  • Cap is 2-6 cm., yellow to bright yellow when fresh, fading to whitish or grayish, sticky, and has grooved margins
  • True gills present on the underside of the cap
  • Spore print rusty brown
  • Stipe (stem) pale yellow and 6-11 cm. long, 2-5 mm. thick
  • Grows alone to scattered

At Edgewood

About

  • Basidiomycetes – a major lineage of fungi that usually produce spores within basidia (club-like structures)
  • Found throughout the year with enough moisture
  • Saprotrophic – grows on dung, compost, straw, and fertilized grass
  • Edibility (San Mateo County Parks prohibits removal of any natural material)
    • Edible
    • Unless you are an expert, do not pick and consume wild mushrooms
Yellow Fieldcap © GBarton

Fun Facts

  • Mushrooms in the genus Bolbitius typically only last a day or two
  • All Bolbitius fungi are saprotrophic, decomposing organic debris or wood

Learn More

Kuo, M. 2021, Mar. The gilled mushrooms. MushroomExpert.Com.

Roehl, T. 2017, Jul. 14. #013: Characteristics of division Basidiomycota. Fungus Fact List. Fungus Fact Friday.

Roehl, T. 2017, Jul. 7. #027: Gilled mushrooms (agarics). 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. 2024, May 18. Bolbitius titubans. MushroomExpert.Com.

Kuo, M. 2023, Nov. 8. The Genus Bolbitius. MushroomExpert.Com.

Wood, M., and F. Stevens. 2024. Bolbitius titubans. The Fungi of California. MykoWeb.