Collection location: Los Trancos Preserve, Palo Alto, Santa Clara Co., California, USA [Click for map]
Ok, kinda sure about these, but not really. These were id’ed with Arora, and in the notes of L. montanum he mentions L. semitale as one that stains grey and black as they age. But he also mentions that they are one of 50 species that do so. If you do a search on Lyophyllum out there, there are hundreds of species, but in Arora there are only 2, so I would say it is not complete… So, I am just tossing these into L. semitale, and it will take lots of better sources and better scope work to get better than that.