These seem to match Aurora's description of Chroomgomphus tomentosus almost exactly . . . except they were growing right under oak (adjacent to redwoods), and in MD he says this species "does not seem to occur in our area." So what could these be? Each cap here is about 6-7 cm across. Observed in Berkeley, CA. Update: sent this one to the MSSF list, and received a resounding cry of Camarophyllus pratensis, which looks a lot like the Wooly Pine Spike, but grows under oak, lives in the Bay Area, and has light spores. Perhaps it's time for me to start taking spore prints, and actually keying out my mushrooms...