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October’s Monthly Mushroom - Blackening Brittlegill (Russula nigricans) and Silky Piggyback (Asterophora parasitica)

October’s Monthly Mushroom – Blackening Brittlegill (Russula nigricans) and Silky Piggyback (Asterophora parasitica)

by Jasper Sharp, 18 October, 2021, 0 comments

I have a love-hate relationship with russulas, the eye-catching, colourfully-capped mycorrhizal mushroom types known commonly as brittlegills. I love it when you chance upon a pristine specimen that has been unmunched upon by insects, slugs or squirrels. It seems impossible to resist the temptation to get down to ground level and take a snap. I hate the subsequent task of attempting to home in on an identification so you can put a label to the resulting photo. Identifying russulas is a painstaking process: determining which of the nearby tree species’ roots in a mixed woodlands it might be forming a mycorrhizal relationship with; in which range of hues does the highly variable cap colour fall within; sniffing to detect if there’s any hint of an aroma such as coconut or crab or strewed apples that goes beyond the simple description of “mushroomy”; the nibble-and-spit test to gauge whether its taste is peppery, acrid or bitter, or any of the other vague categories in between; the thorough examination of physical features such as gill spacing, stem width and how far the cap cuticle peels towards the centre; the rubbing with Guaiac and iron salts to see what colour the flesh changes... And this is before we even get to the microscope stage.  [caption id="attachment_36165" align="aligncenter" width="650"] The Woodland Brittlegill, Russula silvestris, is one of many red-capped brittlegills that need much closer inspection to identify correctly[/caption] Yes, it takes many years in the field to get one’s head around the 200 or so species of brittlegills that have been recorded across the British Isles. Nevertheless, there is one that is not only almost conspicuous within this genus by its utter drabness, but the remnants of its fruitbody, once it has fulfilled its spore-distributing process, leave one in little doubt as to what it is.  That is the Blackening Brittlegill (Russula nigricans), whose fruiting bodies are quite a bit larger than your average russula, getting up to around 20cm across as they expand and flatten out. They start out a grimy off-white colour before darkening through an ever-darkening range of slightly greenish greys and browns before eventually turning completely black. Unlike most fungi fruitbodies, these blackened caps don’t just turn to mush and rot back into the ground. They dry up so as to appear mummified, and you can find their black husk-like remnants lying around for months after the main fruiting season, often well into the following year. [caption id="attachment_36166" align="aligncenter" width="650"] The 'charred' remnants of the Blackening Brittlegill, Russula nigricans, distinguishable due to its relatively wide gill spacing as much as its black colour[/caption] The Blackening Brittlegill might seem pretty unique then, except that the mycological world is never that simple and the world of russulas even less so. In fact, there are a number of other species that blacken and desiccate in much the same way. The Fungi of Temperate Europe (2019) refers to them collectively under the category of ‘charred russulas’, and lists Russula adusta, Russula densifolia, Russula albonigra and Russula anthracina.  The British Mycological Society website includes common names for some of these: R. anthracina is the Coal Brittlegill, in obvious reference to its colour, while R. adusta is the Winecork Brittlegill, as it reputedly smells of empty wine barrels. R. densifolia is the Crowded Brittlegill, due to its tightly packed gills – something which distinguishes it from the Blackening Brittlegill, which has unusually widely spaced ones. When it comes to the taste test, R. acrifolia has hot peppery gills, earning it the memorable title of the Hotlips Brittlegill. [caption id="attachment_36167" align="aligncenter" width="650"] The Crowded Brittlegill before desiccating looks very similar to other charred russulas like the Blackening Brittlegill[/caption] Other features distinguishing these various species include the way the inner flesh colour transforms from their original white when a fresh mushroom is cut in half: R. adusta, R. densifolia and R. nigricans for example turn red then black, while R. anthracina goes straight to brownish black. But let us not get waylaid by any of this, because the main reason for covering these charred russulas this month is due to the way that these or carbonised cap remnants serve as mini ecosystems in their own right as they persist beyond the initial fruiting stage. Look closely and you’ll see them crawling with near microscopic bugs and larvae, and beyond the scope of the naked eye, they swarm with bacteria and other microfungi. This is the case for many decaying fungal fruitbody, it is true, but the charred russulas also provide the substrate for two more conspicuous species of fungi – the Silky Piggyback and the Powdery Piggyback. [caption id="attachment_36168" align="aligncenter" width="650"] The underside of an old Blackening Brittlegill is a haven for insects and other fungi[/caption] I’ve covered a couple of examples of fungi that specifically grow on other fungi in my previous posts on the Bolete Eater, which forms a fishy-smelling bright yellow mould on certain bolete species, and the Common Tarcrust, which plays host to the tiny orange spheres of Dialonectria episphaeria. There’s also a more obviously mushroom shaped example in the form of the Parasitic Bolete (Pseudoboletus parasiticus), which grows out of or in association with earthballs as part of a relationship that doesn’t seem to be clearly understood. However, I don’t think you can find a more striking example of such mushroom-on-mushroom weirdness than the two Asterophora piggyback species. Both are dainty little types that have a similar form and colour to your basic supermarket button mushroom, although their caps only rarely get much bigger than 2cm in diameter and the stems are relatively longer and thinner. The gills of both start off white, then turn brownish. [caption id="attachment_36169" align="aligncenter" width="650"] A group of Silky Piggybacks growing on an old Blackening Russula cap[/caption] The two are pretty similar unless you look very closely, and even then it is not always clear. The cap of the Silky Piggyback (Asterophora parasitica) is fibrous, giving it the silky appearance that gives it its name. The Powdery Piggyback (Asterophora lycoperdoides) is slightly smaller, but its main distinguishing feature is the pale brown dusting on the upper side of its cap. This powder is made up of asexual spores knows as chlamidospores, and is as is noted on the First Nature website, is an unusual feature of basidiomycetes fungi, which produce sexual basidiospores on their gills or in pores (in such examples as the bolete fungi) – the Powdery Piggyback also produces these basidiospores on their gills. [caption id="attachment_36170" align="aligncenter" width="650"] Silky Piggybacks[/caption] One thing that is worth mentioning is that despite the ‘parasitica’ part of the Latin binomial name of the Silk Piggyback, neither are parasitic in any true sense of the word. They are in no way detrimental to their russula hosts. They just have evolved to grow on the long-lasting blackened remains of the various charred brittlegills (they can also be found on the decaying remnants of a number of milkcap species). And so now is the good time to find these curious types. The russulas in general tend to begin fruiting early during the summer months. The Blackening Brittlegill begins appearing in late summer and autumn in both coniferous and deciduous forests, but many will have gone over now and can be seen lying on the ground among the fallen leaves, beech mast, pinecones and other forest litter forming a mushroomy substrate for these two Piggyback species, which you might barely even notice unless you are looking closely at the ground beneath your feet. [caption id="attachment_36171" align="aligncenter" width="650"] Silky Piggybacks[/caption]
August Fungi Focus: Oak Mazegill (Daedalea quercina) and Blushing Bracket (Daedaleopsis confragosa)

August Fungi Focus: Oak Mazegill (Daedalea quercina) and Blushing Bracket (Daedaleopsis confragosa)

by Jasper Sharp, 13 August, 2021, 0 comments

It is good to have points of orientation in the woods. No matter how familiar with a particular spot you might be, these environments can change so dramatically throughout the seasons – paths and clearings become overwhelmed with brambles, branches that weren’t an obstacle in the winter become suddenly more so when covered in leaves, and woodlands are ironically much gloomier in the summer months with a thick canopy overhead than when the trees are bare – that it’s surprisingly easy to lose ones bearings.  One of the marker points in my favourite stomping ground, a chestnut coppice just outside of Canterbury, was a bracket fungus that I found growing from the top of a stump several years ago. It was a relatively easy identification for me from this sometimes daunting group – the labyrinthine arrangement of branching, elongated grooves quickly pointed me towards an Oak Mazegill, despite the fact it was growing on chestnut.  Oak Mazegill For several years, this particular specimen by the side of the path also signalled the point where I knew I’d entered into a sector of more ancient woodland, and one of those hotspot areas where there were usually lots of exciting finds nearby. Then one day it was gone – the clean cut at the base where it grew from the wood indicating that is had been consciously removed with a knife. Even now, about a year later, I can still see traces of the patch where it had endured on the top of the stump for so many seasons. The Oak Mazegill, or Daedalea quercina – the first part of its latin binomial referring to the figure of Daedalus who in Greek mythology constructed the labyrinth at Knossos housing the legendary minotaur – is a particularly prevalent fungi in my local woodlands; much more so because, as a perennial, the fruiting bodies last for years rather than rot back or drop off at the end of the season. It shares this aspect with the tough woody brackets like the Artists Conk (Ganoderma applanatum), covered in passing in a previous post on brackets, which has been known to last for decades. Oak Mazegills aren’t quite as durable, although I’ve no real idea how long a fruit body might last. Their flesh is tough, but still possible to make a clean cut through it with a sharp knife with relative ease, as if it were a piece of rubber. Oak Mazegill This species highlights the importance however of always looking at the underside when trying to identify brackets. The top is rather nondescript, a sort of buff, pale yellowish brown colour ranging to orangish brown and reaches up to 20cm across. They often grow in semicircular tiers, with the full width of the body firmly attached to the wood making them very difficult to dislodge, and sometimes have an upside-down pyramidal shape, so that if viewed in profile, the maze-like underside is very easy to see. The growth isn’t always so uniform, however, drawing attention to the fact that there can often be a fine line between the brackets and certain poroid resupinate or crust fungi, with the form they assume heavily influenced by the orientation of their substrate.  Oak Mazegills don’t always immediately form brackets when first emerging, with the specimen depicted here assuming a more resupinate form. For example, I found myself once very confused by a newly emerged Oak Bracket growing from the top of a  stump that had yet to form a cap, so that all that could be seen was a think bulbous growth covered in brain-like grooves that could look like a number of other thick poroid resupinate fungi, such as the Common Mazegill (Datronia mollis) – and it should be mentioned that the Common Mazegill, while often found in its flat resupinate form, can form caps if growing on a vertical substrate, albeit with thinner caps of a far darker colour. The not dissimilar resupinate fungus the Common Mazegill has a less pronouncedly maze-like pattern of pores Mature Oak Mazegills, I do find pretty distinctive, but the reason I’m covering them for this month is that it is during the summer months that the new fruitbodies start emerging, so if you have any problems identifying them, I’d suggest going back and monitoring their progress over the coming months, for there are a couple of species that you could confuse them with before they are fully grown. The first of these is the Birch Mazegill (Trametes betulina), but these form much more delicate annual fruitbodies which are thinner fleshed and more easily broken, with grooves on the underside that are sharper edged and look more like conventional mushroom gills (although as I described in the post linked above, these aren’t true gills) and a felty upper surface. They also grow on birch, rather than oak or chestnut, so there shouldn’t so much room for confusion here. The Blushing Bracket is less ‘chunky’ than the Oak Mazegill, despite certain similarities when viewed from above. Rather more easily confused for the Oak Mazegill, however, especially in their early stages of growth, is Daedaleopsis confragosa, the Blushing Bracket. Again, these feel a lot slighter, thinner and flatter than the chunky, coarse gilled bodies of the Oak Mazegill, although the flesh is similarly tough.  However the base is much narrower where it grows out of the wood, making it look more fan-shaped. Looking underneath, the pores are much less maze-like, and more like straight lines, which become more elongated as the cap grows radially outwards.  The underside of the Blushing Bracket reveals very different patterns than that of the Oak Mazegill The cap surface starts out a pale beige, but as it grows, it darkens through pinks, browns, russets and vinaceous purples to near black, hence the name. They also are more pronouncedly ‘zonate’, with subtle differences in texture and colour appearing from the centre and outwards. The Blushing Bracket might be confused with a number of other long-pored brackets in their early stages, but if you follow their development across the months leading into winter, it soon becomes clear what they are. Again, they favour deciduous woods, but are less likely to be found on oak and chestnut than on birch, alder and willow. Some of the literature suggests that Blushing Brackets are perennials, like the Oak Mazegills, but my experience suggests that while the new fruit bodies from any given summer may be found well into the winter, very few make it past a year. Blushing Bracket : The upper side of the Blushing Bracket darkens and reddens across the winter months Blushing Bracket : Sometimes reddening to a dramatic deep red These are but a couple of the more common hardwearing brackets with elongated pores that are found in the UK that might seem a little drab when just glimpsed in passing, but actually are quite interesting when you know what you are looking at. Like so many fungi, the exact differences are difficult to describe precisely in words, but once you get a feel for them, they can be recognised at a glimpse.  If you are a regular woodland wanderer, it’s worth paying at least passing attention to them because, as mentioned before, the new fruitbodies will have already begun appearing by now, and given that they’ll be with us for some months yet to come, it’s rather fascinating looking at how both species develop in form and colour. Additional images. Blushing Bracket Oak Mazegill Oak Mazegill Blushing Bracket   
April’s Fungi Focus: Anatomy of a Slime Mould - Trichia decipiens

April’s Fungi Focus: Anatomy of a Slime Mould – Trichia decipiens

by Jasper Sharp, 13 April, 2021, 4 comments

It is that slime mould time of year again, and so a fitting excuse for me to return to a subject so dear to my heart that I’ve already written about it here and here in previous blog posts, as well as authoring a full-length book on the subject entitled The Creeping Garden to tie in with the documentary film of the same name.  In fact it’s always that slime mould time of year, although different species seem to be more prevalent at different points in the calendar. In March and April, for instance, the False Puffball (Reticularia lycoperdon) is commonly reported. At some point very recently it appears to have inherited the common name of ‘Moon Poo’, derived from the Spanish sobriquet ‘Caca de luna’ under which it is known in certain Mexican communities. Its silvery grey blobs, up to 10cm in diameter and with a slightly pinkish sheen, appear around eye level on standing tree trunks, making it particularly conspicuous at a time when other larger fungi have all but disappeared. The vivid sulphurous yellow Flowers of Tan slime mould (Fuligo septica) is more a Summer species. It too seems to have captured the imagination of a certain sector of British nature lovers, who have come to refer to it as the Dogs Vomit slime, although historically this rather unpleasant label has referred in Britain to a wholly different white species usually found on grass, Mucilago crustacea, with its new application making its way over from the North American vernacular. Read more...

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