The Chestnut Bolete, Gyroporus castaneus

 

Towards the end of the afternoon the Field Club members visiting Pilot's Wood came across a small patch of the Chestnut Bolete, Gyroporus castaneus, in amongst Sweet Chestnut mixed with Oak. This is the first time I have knowingly seen this attractive, inoffensive bolete. 

The group of Gyroporus boletes was moved into this genus sitting in its own family because of their really quite unusual cellular morphological features. This is one of two generally recognised UK species, the other being the Cornflower Bolete, Gyroporus cyanescens, a larger and chunkier bolete that is mycorrhizal with a large range of trees across its widespread range, and has flesh that blues quite intensely and quickly. 

Gyroporus castaneus is a generally light to dark brownish and relatively small bolete with white flesh, and very pleasant smell and taste. Thought to exist in Europe, North America, Asia, Africa and Australasia, in other continents it may perhaps be a species complex, based on DNA evidence. One of its stand-out features, shared with other members of its genus, is the tendency of the stem to become hollowed out, firstly in a number of separate chambers and then often completely. The cap and stipe are dry and the stipe does not have dots or a reticulum. The cap and stipe may be fairly brittle and split spontaneously. The spore colour is a straw-yellow - unusual for the Boletaceae.

The pores may darken when pressed, or with age, sometimes to quite a dark brown, but the flesh does not change colour, for example to blue, when cut. The pores are free from the stem.

Although the specific name is castaneus, the name is for the chestnut-brown colour, not its associated tree, and it is I think more generally found in mycorrhizal association with Oak. The geographical distribution covers all 4 home nations, but it is commonest in the southeast of England. 

These particular caps found in Pilot's Wood are lighter than generally expected, but within the potential range. They are mottled, partly concolourous with the stipe which is lighter in colour at the apex than the base, as quite regularly observed.

Showing the spontaneously appearing hollowed out chambers in the stipe:

 

Brown Rollrim, Paxillus involutus s. l.

 

Paxillus involutus (Batsch) Fr. is a very common and also highly toxic mushroom indeed. It'll quite likely get you in the end, destroying your red blood corpuscles after your own immune system is eventually triggered to fatally turn on you.

It is related to the poroid fruiting bodies. The gills become more pore-like as they become decurrent down the stem, and it is said that they are detachable as a layer by pushing with a finger tip at the apex of the stem. 

I couldn't really detect much downiness in either cap, although this is noted in the literature to reduce as the caps age.

Note the brown staining when handled or otherwise bruised. There is indeed a slight umbo in the shallow central depression of the cap in this quite regular cap, possibly not too old a specimen. 

In the second photo, where the cap has been turned upside down, the fluting around the edge as reported in the literature is very clear.

And another larger, somewhat more distorted (a partial rose-comb aberration perhaps?), cap nearby. 

The fluting around the rim of the cap is far more limited in extent in this specimen.

Paxillus involutus s. l. (Batsch) Fr. is a species complex of at least four species, distinguishable by DNA analysis. These fruiting bodies might be the nominate species, as they were growing in more acidic soil and close to Birch, Paxillus involutus s.s.  

Some Sedges at Mereworth Woods, TQ6353 and TQ6354

Along the roadside on Hurst Park Road, this could be more of the Grey Sedge, Carex divulsa, ssp divulsa, with its long slender inflorescence, somewhat shorter lowest bract and overall pale glumes; albeit each with a clear green midrib. Generally for these smaller loose tussocky sedges with drooping inflorescences I think we are looking at Remote Sedge or Grey Sedge, with the odd Spiked Sedge worming its way in from time to time, or so I imagine.

Here are two images of the same clump, one image without Tob's nosey and one with. Noting the dark green of the leaves, sometimes very shiny on the top surface, the overall paler narrow (appressed?) spikes on the spreading stems and the occasional few male spikelets at the top of at least the topmost spike.

.. 

There were several stems taken from the roadside for a closer look, which seemed to more or less confirm the ID, especially the distant lower spikes, although other species and hybrids certainly cannot be eliminated. Issues with this ID are that the lowest bracts are sometimes longer than normally expected, but this is allowed for in the Jermy et al text and in some images I have seen, and that the utricles may develop looking brown to my eyes rather than the described "grey-black".  

However the overall inflorescence is difficult to match to any other species, and the female glumes show the overall pale almost transparent colour with the strong green midribs, acute or acuminate.

The utricles do start off whitish-green, biconvex, beaked, and could, I suppose, be described as diamond-shaped, and their outer bases certainly do show a degree of ribbing, as described.

Moving on to the bridleway. as usual there were fair numbers of individual scattered Pendulous Sedge, Carex pendula on the path-sides, and after this plant, there may have been both seedlings and a number of plants suppressed by drought and compaction that were a fraction of the normal size. 

 

The last species seen today along the path to the right was likely to have been the Wood Sedge, Carex sylvatica, as already listed by the BSBI, although perhaps I should have checked the ligules a little more carefully for the presence of the Thin Wood Sedge, Carex strigosa.

Some Sedges

 

Just by the car park in Dene Park there is an area of grassland where puddles collect above the banks in winter. By one of them is one, and only one, moderate clump of the Spiky Sedge, Carex spicata (Huds). There are two stigmas, the utricles are the right shape, not obviously ribbed, the glumes, or some at least are brown with a central green midrib or wider area, the spikelets are not too distantly spaced, the leaves are the right length, diameter and appear to end in flat tips, the ligules are the right length and shape to separate this from the other members of the Carex muricata group. 

But I cannot see any evidence of vinaceous red on any of the parts, at least as yet. Also, the lower bracts are not really as glumaceous (?) as they are depicted in Jermy et al. 

And this is the end of May, this should not have finished flowering yet!

Scattered through the woodland are clumps of the Wood Sedge, Carex sylvatica (Huds), sometimes in apparently very dry areas. Found in woodlands or possibly where woodlands used to be - maybe thought to be an ancient woodland indicator! Often found on the sides of tracks or in ruts. This is a clump, just the one, from the area of Beech/Oak to the East of the car park. I worried for a while that I might have mistaken this for the Thin-spiked Wood Sedge Carex strigosa (Huds) as the female spikelets did not appear to be pendulous at least at this stage, but the peduncles are clearly too long for that. Well worth double checking though.  Good to see the bright mid-green of the leaves.

Concentrated around one of the junctions of the main circuit, and with a couple of plants also along the Fox Wood path, is the large and distinctive Pendulous Sedge, Carex pendula (Huds). I don't think there is anything else like this on wet and heavy nutrient-rich clay soils. Note the saw-toothed leaves and the long leaf-like bracts subtending the shortly pedunculate but pendulous female spikelets, as well as the untidy terminal male spikelet. Again, possibly fruiting early.   

This is a much more tightly cropped view of the inflorescence shown above.

Along the Fox Wood path, where the pond/partly dammed stream lies out in the field, around the edge there is a good dominating stand of the Greater Pond Sedge, Carex riparia (Curtis), confirmed by the shape of the developing utricles.

A closer view of an inflorescence

These plants were seen previously in 2024, but that was later in the season, with the utricles better developed:

Further downstream, and back in the wood, where the path crosses the culverted stream, there is a uniform patch of the Remote Sedge, Carex remota (L). The spread-out nature of the spikelets in the overall inflorescence is fairly diagnostic (I hope, apart from the Grey sedge, Carex divulsa ssp divulsa (Stokes) to be expected on drier soils probably) and it was nice to see this patch on the softer organic low-lying soil to the side of the stream.

    

Yellow-Cress, Rorippa at Mereworth Woods.

 Along one of the many tracks in the Mereworth Woods complex running North above Gover Hill, I found many hundred basal rosettes of a Rorippa species, almost, but not quite certainly, the Marsh Yellow-Cress, Rorippa palustris. This is an annual or short-lived perennial which appears to generally spread by seed, so it may have had some good years recently. It is much more successful at seed set than its rather more perennial relative, Rorippa sylvestris.

Some of the plants were a bit larger, with some with upright stems bearing some developing flowers, but there were no flowers actually out to measure the size of the petals or compare the relative size of the sepals and petals, and it was far too early in the year for fruit size and shape to be assessed, as the first few were just being formed, so I was unable to be absolutely sure of the identification. I did look carefully at as many of the stem leaves as I could find, and I thought that they were not as fully pinnately divided, nor with the really narrow lobes of the Creeping Yellow-Cress, Rorippa sylvestris, the most likely other Rorippa species that could be found here. Further evidence was the apparent absence of the creeping roots of the perennial Rorippa sylvestris, and the guidance of the KBRG records indicating the presence in this and the neighbouring tetrads of only Rorippa palustris.    

Slightly worrying was the persistence of the rosette leaves. Perhaps this refers to plants that continue into post-flowering or into the second year?

The leaves appear to have been hammered by something like Flea Beetles:

waxy crusts

 

The genus Vuilleminia, named after Paul Vuillemin, is characteristically in the UK considered to be 2 or 3 species of thin waxy crusts that occur beneath the bark of various trees. The commonest would be the very thin, often translucent but with violet tinges, non-cystidiate Vuilleminia comedens which is generally found on Oak, and the two less common lilac-toned but cystidiate Vuilleminia coryli almost always on Hazel, and the chalky-white Vuilleminia cystidiata found on Hawthorn normally. 

This lovely splash of colour along the Access Trail close to Hadlow Village is therefore very likely to be Vuilleminia coryli.  The thin crust is tightly covering the bare wood, and there are thin curled-up patches of bark visible on either side. It has that waxy look!

and in greater close-up, with a bit better light. The small white bumps and the slightly reddish edges of the crust and the red undersides of the freshly turned up bark do match many of the photos on-line.

Its a new species for me and a really gorgeous sight. I am so lucky to have found it!

Ochre Bracket, Trametes ochracea

 

The tan, almost orange in some lights, top, which was just a very slightly felty when magnified led me towards this less common Trametes species, Trametes ochracea, the Ochre Bracket, one that I keep on hoping to find, but rarely get even a hint of. 

Compared to Turkeytail, Trametes versicolor, the clearly thicker individual brackets in fused (not separate) tiers, creamy (not white) shaded pores with well-defined margins about 3-4 (not 4-5) per mm, white flesh with no dark line below the tomentum, and fairly broad attachment making the fruiting bodies quite difficult to pull away from the substrate supported this. This specimen was found on the cut end of a large Birch log in Styants Wood, but the species actually has a wide range of deciduous hosts, including Oak and Beech.

However by this time of year the mushroom fly larvae and others have had a field day and these brackets were in poor condition with a lot of slime and rot apparent. Measuring spore shape and size would help to confirm this less common species of Trametes, so this has to remain just a possible.