This western North American species has long been known by the misapplied name Xerocomellus truncatus (Singer, Snell & E.A. Dick) Klofac (syn: Boletus truncatus (Singer, Snell, & Dick) Pouzar; Xerocomus truncatus Singer, Snell, & Dick). Genetic work by by Frank et al. (2020), has shown that the western North American species is distinct from the eastern North American X. truncatus, and that it is conspecific with a rarely used name, X. mendocinensis (Thiers 1975).
Xerocomellus mendocinensis is a common and widespread bolete in western North America. It occurs in a wide variety of habitat types, from young to mature forests, associating with both conifers and hardwoods. No decline has been observed. We recommend it should be listed as Least Concern (LC).
Currently known from southern California north into Washington, USA. Likely also occurring in northwestern Mexico, and expected into southern British Columbia, Canada (Frank et al. 2020, Siegel & Schwarz 2016).
Population is widespread and stable across the Pacific States in western USA. Occurring in many different habitat types; from young to mature forest.
Population Trend: Stable
Found in a wide variety of forest types. Ectomycorrhizal; commonly in California with Coast Live Oak (Quercus agrifolia) and Tanoak (Notholithocarpus densiflorus), occasionally with other hardwoods or conifers; typically with conifers in the Pacific Northwest. Fruiting from mid-fall into mid-winter, and occasionally in spring
This species is common and widespread in a wide variety of habitats, and no threats have been observed.
This species should be looked for in areas outside the known range; ie. southern British Columbia, Canada, the Rocky Mountains in the USA and Baja California, Mexico.
This species is edible, and occasionally collected for food.
Frank, J., Siegel, N., Schwarz, C., Araki, B. and Vellinga, E. 2020. Xerocomellus (Boletaceae) in western North America. Fungal Systematics and Evolution 6: 265-288.
Siegel, N. & Schwarz, C. 2016. Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.
Thiers, H.D. 1975. California Mushrooms—A Field Guide to the Boletes. Hafner Press: New York, NY. 261 p.
Wood, M. and Stevens, F. 2020. Mykoweb; The Fungi of California. https://www.mykoweb.com/CAF/species/Xerocomellus_mendocinensis.html