Brown Bolete Florida

[diana]

It's been awhile.....  Found a few pretty boletes growing under a loquat tree in the yard.  Russet potato brown cap, very solid.  Cap velvet smooth and very domed.  Pores almost nonexisitant and no depth but a dijon mustard color.  Flesh the color of the yolk of a hard boiled egg (store bought not from yard chickens)  Jeez, is it getting close to lunch time??  Also, no evidence of bugs at all.  Flesh not bitter.  Oh, the stem discolors from handling, flesh does not stain.  Pores don't actually stain but are easily marked but I think that's just from my fingernail.  Smells nutty.

[Dave W]

I don't know the Florida boletes very well, and this is a tricky one because the mushrooms are quite immature (as evidenced by the tightly closed pores and very thin tube layer). You would need to use magnification --like a loupe-- to check to see if the pore openings are stuffed; that is not just merely small and tight by covered with a white "stuffing". The only things that so far come to my mind can be eliminated by one or another feature...

Looks like Caloboletus except species in this genus bruise/stain blue and the flesh tastes bitter,

Suillus species are apt to grow near conifers (with a few exceptions) and the cap is usually sticky or slimy. 

Leccinum typically have a pore surface that's depressed neat the stalk.

The yellowish sheen on the pore surface points away from genus Tylopilus.

The punctate ornamentation on the stalk (I think I see tiny/grainy dots) is wrong for Xanthoconium.

I think we would have a better chance to ID these if more mature fruit bodies were available. 

[diana]

There are still a few growing under the tree,  I'll keep an eye on them.  The ones in the photos - the caps are about 2.5" across.  Picked a one more this evening that is about 4".  My eyes don't work so well this late in the day I'll check tomorrow to see if the pores are "stuffed".  Not too clear on what that means exactly. 😐

[Dave W]

From the Glossary at Mushroom Observer: 

Stuffed Pores:

(Stuffed Pores, Covered Pores, Closed Pores, Stuffed Tubes, Covered Tubes, Closed Tubes)

1. A conspicuous development of cheilocystidia covering tube mouths of young fruit bodies.
2. Conspicuously stuffed in youth as if covered by a complete white membrane.
3. Pores of tubes in youth densely covered with a great number of conspicuously developed cheilocystidia which, in this stage, form a continuous layer on the lower surface of the hymenophore. Under a hand lens this layer looks like ‘hoarfrost’ covering the mouths of the tubes. The tube mouths become distinct only when fruit bodies and their tubes are sufficiently developed.

The reference to "cheilocystidia" is a description of the microscopic aspect. My understanding is that only species of genus Boletus section Boletus exhibit young stuffed pores. I don't think your boletes belong to this category. But, it's a trait worth checking (if you are able to). Is there actually a yellow tinge on the pore surface? Or might this appearance be due to lighting? Is the stem scruffy/punctate? Or is there actually a very fine reticulatum present (threadlike netting)? 

[diana]

This is the last one.  I let it grow.  See attatched photos.

This is exacly why I hate boletes! I thought this one would be easy. I don't even bother with the red capped ones, except for b floridanus which I do feel confident identifying.

It's a mutant. I don't know. Bolete filter for occurring in FL + yellow flesh dns, the only result is Suillus. We are in rainy season and have had a crapload of rain this past week. Not at all viscid. Went onto Mushroom Observer and looked at all the boletes found in the past year. I'd say going by ther looks pictures alone I would guess belonging to the xanthoconium family.

Other characteristics noticed, has been growing as twins often. Mycelium of indeterminate color attached. Pores are indented at stem and do stain a dark color maybe brown. Flesh is a nice texture, firm and not buggy. Stem is thick and pretty even going down. It stains with handling – right away. While the stem is smooth and velvety it does have dots that are not raised at all. Taste is mild with maybe acidic undertones but that could be my imagination. Certainly NOT bitter.

[Dave W]

Xanthoconium seems like a possibility, although the pores/tubes are bit on the green side for that genus.  I'd also suggest Boletus variipes --or something close, there are a few in this group-- except these types all show some reticulation on the stalk. Looks like there may be some Hypomyces beginning to colonize the stalk. So maybe the ornamentation is not evident...? 

I agree, these boletes you find in FL are confounding! It seems there are a number of species that don't occur north of FL, and as such there's not a lot of information available.