Chicken of the woods

 

Chicken of the woods Laetiporus sulphureus, growing on a decaying oak trunk in Backstone bank wood in Weardale’s Tunstall valley. This is the third crop of these spectacular toadstools that has erupted from this tree in recent years. Their webs of fungal hyphae are slowly hollowing out the oak’s trunk, turning it into something with the texture of a crumbly biscuit.

Woodland fungi are a furtive bunch, living mostly unseen under the soil or inside other organisms, digesting whatever their creeping threads can find: nature’s recyclers. Their public appearances are often fleeting, limited to a dusting of rust spores on the underside of a yellowing leaf or overnight eruptions of toadstools in autumn. But bracket fungi are a class apart: big, durable and sometimes a little sinister, and none more so than Laetiporus sulphureus.

Gastronomes relish chicken of the woods as a delicacy, comparable in texture to well-cooked chicken breast, with a rich fungal aroma. So do insects: these are fine young specimens but soon they’ll undoubtedly be full of maggots. Once the dinner-plate-sized brackets were past their best they become chewy and tough, having lost the plump fleshiness of youth.

Six years ago, I picked up a mature fallen chicken of the woods bracket and took it home, to see what might hatch out. Nothing for four days, but on the fifth a blizzard of minute flies swirled out when I lifted the lid of the container. Then, on the 10th day, something special.

It was, I think, a cork moth, Nemapogon cloacella, just 5mm long, scuttling across the surface of the decaying fungus. At first it seemed just another dull, brown micro-moth, but a magnifying glass revealed fringed, upswept wings clothed in scales of mottled brown, white and gold; an insect of exquisite beauty.

Heartwood of oak, created by a sapling’s sunlit leaves perhaps two centuries ago, broken down, molecule by molecule, reconstituted into fungal tissue, then reincarnated yet again as a tiny jewel of an insect.

Beatrix Potter, mycologist

 

When I first became seriously interested in natural history, about 60 years ago, the Wayside and Woodland series of nature guides, published by Warne, were some of the best available, but too expensive for me - the affordable Observer’s books, by the same publisher, were the limit of my budget. Now there are glossier, better illustrated up-to-date guides but the old W & W series often turn up in secondhand bookshops and have a nostalgic charm. This one cost me 50p. in a charity shop and is particularly interesting because most of the illustrations are watercolours by Beatrix Potter, of Flopsy-bunny, Jemima Puddle-Duck, Peter Rabbit and Mrs. Tiggywinkle children’s book fame.

Before she turned to writing children’s books Helen Beatrix Potter (1866-1943) was a passionate mycologist who approached the study of fungi with a scientist’s meticulous curiosity and an artist’s sensibility, encouraged by Charles McIntosh, her local postman-naturalist who often supplied her with toadstool specimens to paint.

Her studies extended to culturing fungal spores in her kitchen and in 1896 she submitted a research paper, on the subject of velvet shank toadstools Flammulina volutipes (pictured below) to the Linnaean Society of London. At that time it didn’t admit women as members but her paper was read at a meeting and returned for revision but never resubmitted nor published.

She moved on to writing and illustrating some of the best-loved children’s stories, devoting the latter years of her life to sheep breeding and conserving the beloved Lake District landscape that was her home, but her mycological legacy lives on in her exquisite watercolours.

The Curse of the Black Spot

 

The curse of the black spot! Tar spot fungus Rhytisma acerinum, that disfigures sycamore leaves in summer, continues to develop on its dead, decaying foliage in the leaf litter. The black spots become increasingly wrinkly as winter progress, then hundreds of asci - microscopically small flasks filled with needle-shaped spores - develop along the ridges. When spring arrives the spores are released into the air, just in time for them to infect a new crop of sycamore leaves, where they germinate and invade through the breathing pores (stomata) in the leaf surface.

Tar spot fungus is less common on urban sycamores that on trees in rural areas and it used to be thought that this was because the fungus was susceptible to sulphur dioxide in polluted city air. A more likely explanation could be that the fungus is less common on city sycamores because their fallen autumn leaves tend to be removed by councils from public places, so the annual cycle of reinfection from dead infected leaves is broken.

Velvet shank

 

Autumn is the main toadstool season but some hardy fungi produce theirs in the depths of winter, even during periods of frost and snow. This is velvet shanks Flammulina velutipes on the trunk of an old lime tree on the bank of the river Wear in Durham city. On mild, wet days the cap is smooth and shiny. The pale stem (stipe) darkens as it matures, developing a velvety texture.

Books say this species is edible when cooked. John Wright, the The River Cottage Mushroom Handbook described the flavour as ‘unusual ….. distinctly sweet and malty’ and the texture ‘pleasantly chewy’ but cautions against mistaking it for sulphur tuft (gastrointestinal devastation) or the funeral bell (the essential caution is implicit in the name). Velvet shank differs from both in having white spores.

 

Larch bolete Suillus grevillei

 

These caramel-coloured larch boletes Suillus grevillei began to appear around the roots of larch trees in the Deerness valley this week. They are said to be edible, but those slimy caps are unappetising and it’s their biology rather than their flavour that I find interesting.

This is a mycorrhizal fungus, living in close association with larch tree roots, increasing their ability to absorb minerals from the soil in exchange for sugars from the tree that fuel the fungal growth. It exists for most of its life as a mass of hidden hyphal threads, thinner than human hairs, but early autumn provides a signal for a switch to reproductive growth, reorganising its weft of threads into these elegant toadstools.

When they first break through into the daylight the underside of the cap is covered with a veil that ruptures when the cap expands, exposing the spore-producing tissues.

In boletes the spores are produced inside thousands of fine tubes on the underside of the cap, that open via pores, to release the spores into the airstream.

To appreciate the beauty of the pores, and marvel at what finely-uned organisms toadstools can be, you really need to take a close look at their surface with a hand lens, and then …

… slice down through the cap with a razor blade, to expose the vertically-aligned tubes. In order for these to function effectively the microscopically-small spores lining the tubes must be able to freefall down and out through the pores, unimpeded, into the airstream. This depends on the toadstool’s finely tuned perception of earth’s gravitational pull, so that the tubes are always perfectly aligned with gravitational force; any deviation and the tubes would become clogged with spores that would stick to their walls. When toadstools are tilted, growth of the tubes (and gills of toadstools that have those) is quickly readjusted, to bring them back into vertical alignment.

So could you grow functional toadstools in outer space? For decades scientists have contemplated the potential for growing fungi in microgravity, to feed space travellers but its doubtful whether these beautiful, gravitationally-sensitive, aesthetically-pleasing toadstools would grow. There is, though, a SpaceX experiment in progress to see if toadstools will form, using oyster mushrooms (which have gills, not pores), in the microgravity environment of an orbiting space station.

Dryad's saddle rides again

 For the fourth time in a little over two years this old sycamore stump has produced a magnificent display of dryad's saddle Cerioporus squamosus bracket fungi. The previous crop appeared this spring, in April.

It's likely that the fungus was the original cause of death for the mature tree, which must have been felled as a safety precaution since it was growing close to a road.  The fungus has been digesting its remains every since.

In classical Greek mythology 'Dryades were nymphs that presided over the woods. Oblations of milk, oil, and honey were offered to them, and sometimes the votaries would sacrifice a goat. They were not generally considered immortal, but as genii, whose lives were terminated with the death of the tree over which they were supposed to preside.' J. Lempriere. A Classical Dictionary: containing a copious account of all the proper names mentioned in ancient authors. Originally published in 1788.

The underside of the cap, with thousands of tiny pores releasing millions of spores.

Exquisite pattern of scales on the cap of a bracket.

Choke fungus - Epichloe typhina

These strange white sheaths around the stems of grasses are the spore-producing tissue of the fungus known as choke Epichloe typhina. It's present inside the grass all year-round, living as microscopic hyphae within the spaces between cell and benefitting from sugars produced by the host's photosynthesis, but is only visible to the naked eye in summer, when it produces its spores externally around the stem. The white fungal sheath will turn orange-brown when the spores are ripe and ready to be shed, when they are often carried away by small flies.

 The fungal infection tends to prevent the grass culms from flowering, promoting multiple shoot formation instead, but in return the fungus increases its host's drought resistance and produces toxic alkaloids that deter grazing animals, so the relationship between fungus and grass is symbiotic and not simply parasitic.

I found these specimens growing beside a footpath at Wolsingham, Weardale this week.

Shaggy scalycaps

 We found these magnificent shaggy scalycaps Pholiota squarrosa growing around the base of a mature ash tree in Auckland park, Bishop Auckland. They've appeared in the same place for several autumns now and I wonder how long it will be before they weaken the roots so much that the tree will come crashing down in  gale.

 I've also seen shaggy scalycaps growing on old beech trees in the park - these were growing inside the hollow trunk of a beech that died long ago.

Pocket plum disease

 This summer there have been some spectacular local outbreaks of pocket plum disease, affecting sloes on blackthorn on the Durham coast near Hawthorn dene  and bird cherry fruits in Weardale. It's caused by the fungus Taphrina pruni, which induces the fruits to swell, become spongy and fill with watery fluid. In bird cherry (bottom picture) the normally spherical, shiny black fruits become banana-shaped. No seeds are formed inside these deformed fruits, instead there is an empty 'pocket'.

Some late winter toadstools

 Three late-winter fungi that have been very conspicuous here this month.

 Scarlet elf cup Sarcoscypha austiaca. Always a joy to find, especially when it's nestling in a bed of mosses. More about this species here.

Hairy bracket Trametes hirsuta, on the base of a dead silver birch trunk. Seems to be increasingly common hereabouts.

A nice cluster of very young velvet shanks Flammulina velutipes, on a dead poplar stump. A toadstool that continues to grow in the coldest, frostiest weather.

Waxcaps in Auckland park, Bishop Auckland

 

This has been the best autumn for waxcap toadstools that I can recall here in County Durham. This very mild, and lately very wet, November seems to have suited them perfectly.

I found these in ancient, unimproved calcareous grassland in Auckland park, Bishop Auckland this morning. I suspect that the one above and the two below might be the scarlet waxcap Hygrocybe coccinea, whilst the bottom two photos, with yellow gills, could be crimson waxcap Hygrocybe punicea, though it is hard to be sure. 

These exquisite little toadstools often seem to be associated with meadow ant nests in the park, which could have more to do with soil drainage than directly with ants. They toadstools are brittle and many are knocked over and broken by grazing animals.

local patch lockdown: some plants

The end of three weeks of Coronavirus lockdown early morning walks around the same route. After a slow start, when spring seemed reluctant to release its grip, suddenly everything is coming into leaf and now there are more flowers opening every day. 

This Pulmonaria is a garden throw-out, dumped with some garden waste, and has established itself as a large patch of flowers on the road verge. Tt has been flowering since mid-March. 

The first blackthorn blossom appeared in mid-March and by early April the hedgerows were looking lovely.

There is one large wych elm tree on my route, that has escaped Dutch elm disease and by early April it was in full bloom.

There are a lot of Prunus species in the hedgerows along the route and I'm guessing that these are all cherry-plum

This one looks like blackthorn, but it's a small tree. Blackthorn rarely grows to these proportions.

Silver birch catkins began to bloom in early April and by mid-April the leaf buds were beginning to burst

Wild cherry in bloom - one of the finest of all our native flowering trees

Male (above) and female (below) sallow, flowering

Female flowers of an unidentified willow

Ash in full bloom. It will be three or four more weeks before the leaf buds burst. This is always the last tree to come into leaf and the first to lose them, in September.

Lots of gorse in the hedges around the route and also some good gorse scrub - excellent, prickly nest sites for birds

The hawthorn hedges began to show the first signs of new leaves in late March

Rowan leaf buds burst very early and are already showing well developed flower buds

The colt'sfoot that has been flowering since mid-March is now going to seed

White dead-nettles and greater stitchwort flowering on the road verges in mid-April

Not many fungi at this time of year, but these are old, withered specimens of yellow brain fungus Tremella mesenterica growing on a moss-covered dead stem of gorse.

An attractive example of turkey tail fungus Coriolus versicolor

Not sure about this one, but I think it might be an old specimen of hairy bracket Tremetes hirsuta