Described from an Oregon, USA type collection (Hesler & Smith 1979).
There is some question if the sequestrate species, Lactarius desjardinii (Thiers) P.M. Kirk is distinct or not. More research is needed.
Lactarius pallidiolivaceus is a widespread but uncommon species, occurring in mixed Tanoak-conifer forests in northern California and southern Oregon, USA.
Data to assess trends is lacking. There are also taxonomic issues regarding the sequestrate species, Lactarius desjardinii, and if it represents a distinct species.
At this time, I suggest listing as Data Deficient (DD).
From Santa Cruz County California north into central Oregon in coast and Coast Range forests, also in the northern Sierra Nevada foothills.
Population is widespread, occurring in northern California and southwest Oregon in mixed evergreen forests. Uncommon to rare, but widespread. Data on populations and to track trends is lacking.
Population Trend: Uncertain
Ectomycorrhizal, occurring in mixed evergreen forests on Northern California and southwest Oregon. Likely associated with Tanoak (Notholithocarpus densiflorus), possibly Madrone (Arbutus menziesii) or Douglas-fir (Pseudotsuga menziesii). Fruiting in fall and winter
No specific threats have been identified with regards to this species. However it is uncommon, and any decline should be noted.
No specific conservation actions is needed with regards to this species at this time.
Genetic research into semi-sequestrate and sequestrate collections, and how they compare with Lactarius desjardinii. More data on this species to track trends and populations,
Hesler, L.R. and Smith, A.H. 1979. North American Species of Lactarius. University of Michigan Press: Ann Arbor, MI. 841 p.
iNaturalist. 2021. Available at: http://www.inaturalist.org
Methven, A.S. 1997. The Agaricales (Gilled Fungi) of California. 10. Russulaceae II. Lactarius. Mad River Press: Eureka, CA. 79 p.
Siegel, N. and Schwarz, C. 2016. Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.