Collection location: Albion, Mendocino Co., California, USA [Click for map]
Ok, this one. It came in and it was rather large, pileus ~14 cm across, ~5 cm thick. But the feel of the mushroom, was different than anyone we found before. Only the pores stain blue, not the pileus or stipe. And later when I cut in half, the flesh did not stain blue when bruised. Only the flesh near the pores very slowly slightly stained blue. The taste of the flesh was very mild. One interesting feature, there was a layer of brick/vineasous red under the pileapelus (how do I spell that?). You can see a little of this in the photo where there are a few nips out of the edges of the pileus.
The species of B. smithii was roughly placed up at Albion, and I took these home to look at the Boletus of CA. online:
From the field key, B. spadiceus seemed to match these. It does have the red layer in the cap, and the slightly bluing near to the pores only. But these are too large for the description, and the red on the stipe is not mentioned. Also B. fragrans comes close, it better matches size, and has the red on the stipe, but not the red layer in the cap. Also B. fragrans is listed as only a montane species, that has only rearely been found. So, none of these are really satisfactory.
But going back to B. smithii, the description does match these rather well, with the red layer in the cap, and esp. with the rad band at the top of the stipe. But smithii is supposed to blue stain in the flesh, and these didn’t do that much. But I was cutting it up 24 hours later, and in other species the blue staining can go away after getting the sample out of ground, so don’t know. Also I am used to crysenteron, where the amount of bluing in the flesh is quite variable.
The one place the field key went a little wrong with these, was that they are supposed to have a red/pinkish cap. In the comments it does mention that they are usually olive/brown/gray in the cap, but this layer wears off as the species grows and the under red layer starts to show through, giving them a pinkish/red cap look. These are fresh enough to not quite show the red layer in the cap very much.
The description also mentions that these are more common in Oregon and Washington area, but are common enough in the coastal area of CA in Mendocino Co under conifers, but nowhere else in CA. So, in the end, B. smithii sounds good to me.