Recent monsoonal flows and thick marine layers created opportunities for clusters of these. Overstory is redwood, tan oak, and huckleberries (the latter a bit early with fruit).
Was sure this was Pluteus longistriatus until I picked it and saw the base.
Bottle-green caps quite rugose when young. Fading to golden-olive brown. Stipe yellow.
Infrequent on tanoak. I have also seen this on the UCSC Campus.
Added micrographs of spores, size approx. 12-13 x 6 um. Pileipellis lacking setae (NaOH).