Exsudoporus frostii (Frost’s Bolete)

August. I saw Frost’s Bolete (Exsudoporus frostii; formerly Boletus frostii) for the first time on another trail in the park.

They were easily visible from the trail. Two ‘shiny’ red caps. The caps of young Frost’s boletes are sticky. 

When I turned one over, I could see the red reticulate stem and the red pore surface. (The fluid isn’t unusual in young specimens; older specimens usually have dry pore surfaces.) It didn’t take long to identify this species. 

I’ve since found it in several locations near the trail north, but not south, of the Fishing Area.

This beautiful specimen was growing between the trail and the reservoir shore.

Another older specimen, with a still somewhat shiny cap, was growing beside the trail.

The reticulation on the stem is much more pronounced, but less pigmented, in specimens as they age. The pore surface becomes brownish in older specimens although they still develop the deep blue/black color that results from bruising, when a colorless compound called boletol is exposed to air and oxidized to a blue color.

I’ve mentioned, on occasion, that I often sit or lie on the trail to take photographs. I was lying just past a slight bend in the trail when I took this photo. A tree in the bend hid me from other walkers on the trail. I became aware of a walker cautiously approaching, just out of eyesight. I realized that they could only see my legs and feet, and were probably wondering if they were encountering a body on the trail. I sat up and let them know I was a living creature. We laughed. This isn’t the first time other walkers have wondered if I was OK, but this was the funniest occurrence, depending on how you look at it.

Exsudoporus frostii had been found widely in eastern North America, Mexico, and Costa Rica.

References: 

Mushroom Expert: Boletus frostii 

Discover Life: Boletus frostii

Tylopilus plumbeoviolaceus (Violet Gray Bolete)

August. The Violet Gray Bolete (Tylopilus plumbeoviolaceus) is another bolete that might easily be overlooked. This one was growing in the ‘island’ created when the trail went on both sides of a tree in a primarily hardwood forest.

From a distance it didn’t look like much. However, up close it was elegant in its shape and colors.

Its cap was brown, approximately 3 inches in diameter, convex, and smooth.

The pore surface was white. Its stem tapered from larger at the base to small at the apex. The stem looked gray from a distance but when viewed up close, was a delicate purple streaked with white.

Its pores, 2-3/mm, were angular with relatively thick walls, and also had a translucent appearance. 

I found only two specimens of this species: this one in the center of the trail, and another in the woods away from the main trail. Both observations were made north of the Fishing Area. 

Tylopilus plumbeoviolaceus appears to be distributed widely in eastern North America although a couple of observations have been made in Central America and Korea. 

References: 

Mushroom Expert. Tylopilus plumbeoviolaceus 

The Bolete Filter.  Tylopilus plumbeoviolaceus (“Violet Gray Bolete”) 

Discover Life. Tylopilus plumbeoviolaceus

Retiboletus ornatipes (Ornate-stalked Bolete)

August-September. I’d never seen an Ornate-stalked Bolete (Retiboletus ornatipes, formerly Boletus ornatipes), until this year. The first one was located where I couldn’t photograph it. But the second one made sure I saw it – in the end.

It didn’t look like much from above and I had missed it when I first walked along the trail. It blended well into its surroundings.

However, it certainly stood out in profile. I spotted it from a distance when I was walking back along the trail. I couldn’t believe that I’d missed it when I passed by it the first time. It was growing from exposed roots in the trail. Its cap was a dun brown, broadly convex, and smooth. I had to sit down on the trail and photograph it. 

Retiboletus ornatipes is one bolete that is easy to identify from the stem alone. Michael Kuo (Retiboletus ornatipes) describes the stem as ‘… prominently and coarsely reticulate with a yellow reticulum that becomes brownish with age or handling.’ I like the description in Roger’s Mushrooms (Boletus ornatipes) better, ‘Stem... surface with a prominent network, or reticulum, or raised ridges.’ The specimens I’ve seen have ‘smooth’ stems with raised ridges that bruise brown with age or handling.

The pore surface was bright yellow with large pores (1-2/mm), easily visible to the naked eye.

The caps of old specimens were darker in color and often cracked to reveal the yellow flesh. Their stems were dark brown; a close view of the…

surface of the stem showed that the ornate reticulation was still intact and sharply delineated.

The pores of old specimens, that in this case hadn’t been bruised, had dried and had shrunk into an interesting pattern. 

With most observations, I see a particularly specimen on one week only; rarely do I get the opportunity to see the same specimen on two successive weeks. I was, however, fortunate to have this opportunity with one specimen of Retiboletus ornatipes.

A young specimen that still had a light yellow cap and a pristine stem with ornate reticulation and no bruising.

A view of the pore surface and the stem. The pores were still blocked.

A week later, the cap was broadly convex and tan. The ridges that formed the reticulation were bruised brown.

A close view of the stem showed the brown-bruised stem. The ornate reticulation, however, was still quite evident. 

This was the only species that I found at various places along the entire length of the trail. I found it at three locations: near the beginning of the trail; midway along the trail, above the cliff; and at the northern end of the trail not far from the Old Fort. 

Retiboletus ornatipes is limited, geographically, to eastern North America. Specimens of related species have been found in Central America. 

References: 

Mushroom Expert:  Retiboletus ornatipes 

The Bolete Filter: Retiboletus ornatipes (Ornate Bolete) 

Roger’s Mushrooms: Boletus ornatipes

Boletus pallidus (Pallid Bolete)

August-September. The first Pallid Bolete (Boletus pallidus) I saw was growing at the edge of the trail in the woods just north of the beach. It appeared to be growing in the soil some distance from any tree. However, since boletes are mycorrhizal – have a symbiotic relationship with tree roots – it was probably growing on roots from one of the nearby oaks. 

I might not have taken much notice of this unassuming bolete except for the fact that…

it was in beautiful condition. I sat on the trail and photographed it.

Its cap was buff to pale tan-colored and approximately 2.5 to 3 inches in diameter. Caps of Pallid boletes may range from white to pale tan; sometimes they may have rose-colored tinges. 

The stems of these boletes are usually equal in diameter along their lengths, are white but may develop brown streaks. Stems are considered to be smooth, not showing any reticulation. The stem of this particular bolete was approximately 3 inches long, tapered from the base to the apex, was pure white, and smooth although showing some ‘dimpling’.

The pore surface of this first find was white and slightly translucent and showed some yellowing near the stem. The pores were relatively large, 2-3/mm. The pore surface bruised brown when damaged. 

I found two Pallid boletes a week later.

The first of these had a more convex and darker cap, but exhibited the same plump stem. 

The second exhibited a broad convex, almost flat, cap with a stem that was narrower in the middle than at the base or apex. 

Later, in early September, I found a couple of Pallid boletes growing on rotting wood.

This bolete had an almost flat cap. Notably the stem was almost the same diameter along its length.

Its pore surface was a grayish-cream color due to the color – olive to olive-brown - of the spores that had been released, and also showed grey-blue bruising near the margin. Brown streaking was also obvious on its stem. At the base of the stem, the white mycelium of this species was clearly visible.

A closer views of the pores shows both the blue-gray bruising of this surface and the angular shape and density (2-3/mm) of the pores.

In contrast to the other Pallid boletes I found, this bolete had a white cap. Its pore surface was discolored by spore release and its stem was tapered and exhibited brown streaking. The white basal mycelium was visible at the base of the stem as well as emerging from the wood near the base of the stem. 

Once I’d identified the first Pallid bolete, it was easy to recognize them in spite of the variability of cap color and stem shape. I found all but one of these specimens in the woods by the south end of this trail. I found the last specimen at a distance from the trail north of the Fishing Area. 

Boletus pallidus has been documented from North America and Australia. 

References:

Mushroom Expert: Boletus pallidus 

The Bolete Filter: Boletus pallidus 

Discover Life: Boletus pallidus

Tylopilus rubrobrunneus (Reddish Brown Bitter Bolete)

August. I found only one specimen of…

Tylopilus rubrobrunneus (Reddish Brown Bitter Bolete). It was growing near hardwoods just to the side of the mountain bike/hiking trail that runs parallel, a little higher up the hill, than my routine trail close to the shore of the reservoir. It was quite tall compared with the diameter of its cap. A ‘regal’ bolete.

 

Its cap was approximately 2.5 inches in diameter and a distinct purple-brown. The irregularities in the cap are thought to be the result of a parasitizing fungus.

The pore surface was pure white and translucent. The pores were angular and clearly visible with the naked eye, approximately 2-3 pores/mm. The purple color at the margin of the cap, is clearly visible in the first of these two photographs.

The stem was whitish-brown, tapering from the cap towards the base. The effects of the parasitizing fungus are clearly visible in this photograph. The stem looked smooth, but showed some…

reticulation that was visible at the apex of the stem near the cap. 

Tylopilus rubrobrunneus is found only in North America, east of the Rocky Mountains.

Related post: 

Bolete Mushroom Season Is Here Again 

References:

Mushroom Expert: Tylopilus rubrobrunneus 

The Bolete Filter: Tylopilus rubrobrunneus (Reddish Brown Bitter Bolete) 

Discover Life: Tylopilus rubrobrunneus

Heimioporus betula (Shaggy Stalked Bolete)

August-September.  Heimioporus betula, the Shaggy Stalked Bolete, is probably

the easiest bolete to identify along the trail from the beach to the Old Fort in Fort Yargo State Park.

The dead give-away to identifying this species is the coarsely reticulated stalk. This photo shows a particularly pristine stem that becomes more 'shaggy' with age. The red color under the surface is also characteristic for this species.

Young specimens growing have caps barely wider than the stalk. When in deep shade their caps are deep orange. Specimens growing in open woods have a lighter orange-colored cap. In either case, the caps of young specimens are sticky. The caps usually enlarge to be wider than the stalk.

As they age, the caps become dry and start to lose their deeper orange color.

Ultimately, the caps become yellow-colored.

The pore surfaces of young caps are irregular with large angular pores, 1-2/mm.The pore surfaces don't bruise blue when damaged.

The pores become ragged as they age and discolored by olive to olive-brown spores.

The red color under the surface results from a ring of color immediately under the surface, that...

diffuses throughout the stalk with age. 

Shaggy stalked boletes may be solitary or scattered over a small area. It was unusual to find… 

this pair growing closely together. 

So far, I’ve only found most specimens in wooded areas between the beach and the Fishing Area. This year, I did find two small specimens just north of the Fishing Area, away form the main trail. 

Heimioporus betula has been reported only in North America. 

Related post:

Bolete Mushroom Season Is Here Again 

References:

Mushroom Expert: Heimioporus betula

Discover Life: Heimioporus betula