Collection location: Los Trancos Preserve, Palo Alto, Santa Clara Co., California, USA [Click for map]
Ok, these are mild tasting, and the gills from off white when young to deep ocher-orange in age. So, they fall into the mild, yellow spores group. With the white color, not yellow, this falls into two species in the Thiers’ monograph : R. albida and R. basifurcata.
They are seprated by the fact that R. albida doesn’t have reticulation in the spores, and the cap surface is smooth, without cystidia. R. basifurcata has reticulated spores, and lots of cystidia on the cap surface.
You can see that here in the micro-shots. The first one is at 1000x with Meltzer’s reagent, and it is of a pair of spores. The spores show amyloid reticulation, with kinda smallish warts. The reticulation doesn’t seem complete, but it is clearly there.
The second micro-shot is at 400x, under KOH, and this is of the cap surface. The surface shows lots of cystidia as the hairy extensions. I’m not sure still how to get the thickness of the cuticle from this.
So, using Theirs’ monograph, this clearly id’s it as R. basifurcata. Which I’ll go with.