Aureoboletus citriniporus is an ectomycorrhizal bolete occurring in oak woodlands, especially with Coast Live Oak in the greater San Francisco Bay Area. Recent reports are mostly from the Bay Area and Santa Cruz. Historic collections come from the Sierra Nevada foothills (MyCoPortal 2020), but no recent records are reported (iNaturalist 2020, Mushroom Observer 2020). About ~40 locations are currently known. Although limited data are available showing trends of this species, it has experienced population decllne in the past due to habitat loss, and this decline is ongoing due to continued urbanization, coupled with a continuing decline in habitat quality due to impact of sudden oak death on its host tree and impact of invasive grasses. Taken together these threats are causing a significant decline in the species leading to an assessment of NT.
Described as Boletus citriniporus (Halling 1977), from a California, USA collection made in the Sierra Nevada foothills, later transferred to the genus Aureoboletus (Klofac 2010).
Aureoboletus citriniporus is an ectomycorrhizal bolete occurring in oak woodlands, especially with Coast Live Oak in the greater San Francisco Bay Area. Recent reports are mostly from the Bay Area and Santa Cruz. Historic collections come from the Sierra Nevada foothills (MyCoPortal 2020), but no recent records are reported (iNaturalist 2020, Mushroom Observer 2020).
The species is endemic to the western United States. Most records come from Santa Cruz County through the San Francisco Bay Area, north to Sonoma County, California, USA, with scattered records in the Sierra Nevada foothills. There is a single record reported from southern California (MycoPortal 2020), and one from Corvallis, Oregon (N. Siegel pers. comm.).
Population is mostly centered from Santa Cruz County to Marin County, California, through the San Francisco Bay Area; an area that is a highly developed under urban sprawl. Other scattered reports come from the coastal California counties north to Humboldt County, the Sierra Nevada foothills, and a single location in Corvallis, Oregon. About 40 locations are currently known. Although limited data are available showing trends of this species, it is likely decreasing due to habitat loss, decline in its host tree due to disease, and decline in habitat quality due to invasive grasses.
Population Trend: Decreasing
Ectomycorrhizal with oaks (Quercus spp.), especially Coast Live Oak (Quercus agrifolia). Typically in stands of oak with thick duff, or duff buildup, without a grassy or weedy under story. Fruiting from fall into winter.
Sudden oak death, caused by Phytophthora ramorum has been spreading through California’s oak woodlands, causing considerable mortality in some regions. Urban development has lead to significant loss of habitat. Invasive plants, especially grasses growing in oak woodlands are degrading the habitat..
Additional oak woodlands in the Bay Area need protection. Better management, especially in control of invasive plants in oak woodlands is needed.
Additional surveys for this species in southern California, and the Sierra Nevada foothills to better document its distribution and population size would enhance conservation efforts.
This species is edible, and occasionally collected for food.
Halling, R.E. 1977. California Boletes VI. Some unreported species from the Sierra Nevada of California. Mycologia 69: 206-210.
iNaturalist. 2020. http://www.inaturalist.org
Klofac W. (2010). Die Gattung Aureoboletus, ein weltweiter Überblick. Ein Beitrag zu einer monographischen Bearbeitung. Osterreichische Zeitschrift fur Pilzkunde 19: 133–174.
Mushroom Observer. 2020. https://mushroomobserver.org/observer/map_observations?q=1a8f8
MyCoPortal. 2020. http://mycoportal.org/portal/index.php. Accessed on December 29 2020
Siegel, N. and Schwarz, C. 2016. Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.
Wood, M.G. and Stevens, F.A. 2020. MykoWeb; California Fungi. https://www.mykoweb.com/CAF/species/Aureoboletus_citriniporus.html