Mushroom of the Month, July 2010

Quite a rare find, Boletus parasiticus (synonym: Pseudoboletus parasiticus) is commonly referred to as the parasitic bolete. It is always found with common earthballs, Scleroderma citrinum. That seems to suggest that this bolete consumes the earthball to which it appears to be attached, and yet some scientists are now suggesting that the relationship may not be parasitic after all. Well, perhaps so, but I remain to be convinced: just look at how the earthball in the picture above appears deflated, as though something is consuming its innards.

There seems to be little dount that Boletus parasiticus cannot live without its earthball associate, and every specimen that I find is with an earthball partner. Often a single earthball is 'host' (if that is an appropriate term for the true relationship between these two fungi) to several fruitbodies of the parasitic bolete. Parasitic boletes are hard to find, and stumbling across a patch of common earthballs is no guarantee that you are about to see this rather dull and unimpressive member of the family Boletaceae: most earthballs occur without parasitic boletes.

If you ever go across the sea to Ireland, as the song says... some way south of Galway bay is the lovely town of Killarney and its nearby lakes and mountains. Within the woodland there, and most particularly near Mucross Abbey, common earthballs line many of the drainage ditches, and quite a high proportion of those earthballs have parasitic boletes attached to them.

Where else is good? Well. my favourite hunting ground is in the narrow strip of woodland along the gorge of the River Teifi at Henllan, in West Wales. There, every year, while hunting rare fungi and lichen I come across dozens of parasitic boletes with, of course, common earthballs.

I have looked out for these intriguing boletes in so many other places and failed. The New Forest, in southern England; the Caledonian Forest, in Scotland; the Forest of Dean, in the Wye Valley; numerous pinewoods in France, Portugal, Bulgaria... But of course, not finding them doesn't mean that they are not there. These are fairly inconspicuous fungi, almost always in deeply shaded habitats with plenty of leaf litter, with which backgrounds they blend in very well.

One final point... this is always a woodland mushroom, as indeed are most if not all other boletes. The common earthball, Scleroderma citrinum, is ectomycorrhizal with both hardwood and softwood trees (broadleaves and conifers), meaning that it lives in a mutually beneficial relationship (termed symbiosis) with the fine rootlets at the ends of the roots of trees. The fungus in effect feeds the tree and the tree also delivers vital chemicals to the fungus. Meanwhile, within this ménage à trois, the parasitic bolete is also up to something, and I suspect it is up to no good! How often we find that these interrelationships between fungi and plants are far from simple. For example the rare wild orchid Limodorum abortivum is now known to depend on certain kinds of Russula fungi which themselves require pine trees - explaining why the violet limodore, to quote the orchid's common name, is found only beneath pine trees.

We certainly do live in an amazing (and amazingly complex) world.

Do let me know if you are able to add to (or correct) any of the above...

Happy hunting!

Mushroom of the Month - June 2010

I had to rub my eyes the first time I saw a group of Woolly Milkcaps, Lactarius torminosus, in bright sunlight beneath a tall silver birch tree. They are the archetypal Tellytubby mushrooms - perhaps even more so than are the Fly Agarics of fairytale fame - and equally dubious as a source of food. One common name for this relatively uncommon mushroom is Poison Powderpuff. Enough said? (Actually, torminosus means 'cause of colic', and so the scientific name is also a warning.)

The Woolly Milkcap generally occurs either solitarily or in small scattered groups, always with trees and almost invariably close to birches in grass-covered glades and woodland edges. One on the larger fungi in this genus, Lactarius torminosus is one of the easiest species to identify without microscopy or chemical tests - some of the smaller milkcaps can be very tricky - and the only common species with a similar woolly cap is Lactarius pubescens, also associated with birch trees. Full details of both species can be found on www.first-nature.com/fungi

All Lactarius and Russula fungi - the Russulaceae family - are ectomycorrhizal: they form mycorrhizae that sheath the tiny rootlets of trees or shrubs. Through these mycorrhizae the fungi and trees exchange chemicals in a mutually beneficial (symbiotic) process. More about that and many other fascinating facts about mushrooms, toadstools and the like in my forthcoming book on fungi due out later this year... watch this space (blatant self publicist!).

Pat

Mushroom of the Month, May 2010

Where did April go to? No blog post... because we were away photographing wild orchids on Crete and then on the Gargano Peninsular, Italy. And we should add that the wildflowers, including dozens of orchid species, were absolutely marvelous. We are continually adding pages to the Wildflowers section of the First Nature website, so that's the place to go if you are a wild orchid fan. Meanwhile, what about an early season mushroom for May... well, there are plenty to choose from. St George's Mushroom, supposed to appear on 23rd April but rather delayed because of the cold winter and delayed spring, is now in evidence, but that was the subject of this blog a year ago (Mushroom of the Month, April 2009), so here's another mushroom that is easy to find in May; and it is a useful edible mushroom at that!


Auricularia auricula-judae is known as the Jelly Ear Fungus (or, perhaps less politically correct but nevertheless a strict translation of the scientific name, Jew's Ear). To find these rubbery (in anything but very dry weather, that is) purplish-brown fungi you need to look on dead elder wood - either standing or fallen trunks and branches that have decayed to the point where the bark is peeling or has fallen away. Shady, damp places are generally best of all.


A plate of these fungi would make a very disappointing meal, but if you add a few, chopped into thin strips, to any other mushroom dish the jelly fungi take in the flavour of the rest of the dish and add a very pleasant 'al dente' element. (There may be other ways of cooking Jelly Ear Fungi that we don't know about, so if you do then please post a message to this blog, as we are always interested in new recipes for nice fungi dishes.

Mushroom of the Month, March 2010

The tarmac surface of an old road is no barrier to this determined mushroom!

Pisolithus tinctorius (synonym: Pisolithus arrhizus) is an ectomycorrhizal earthball, sometimes referred to as a dyeball - a reference to one former use for the mature spore mass that this mushroom produces.

Up to 20cm tall, the fruitbodies burst through dry ground and eventually turn into a brown powdery mess that blows away on the wind or gets carried away by rain. Most common in southern Europe but occasionally seen in the UK, these massive fungi have another extremely valuable use: they form mycorrhizal associations with just about any plant that can be grown in soil, and so they are used to produce 'mycorrizal inoculants'. The fungi in effect feed the plants, scavenging vital minerals from the soil via tiny mycelial threads that in effect extend the plant's root system. The fungi also gain nutrients from the plant's photosynthesis process. This is termed a symbiotic relationship.

Here is a picture of the inside of a young specimen of Pisolithus tinctorius:

The spore-producing material looks like rice grains densely packed together. At maturity the appearance is not unlike a pile of rotting horse dung. The one shown below is splitting open and the brown spore mass can be seen:

Foresters use an inoculant made from Pisolithus tinctorius to help young conifers (especially pines) get started on poor or contaminated soil that has lost or perhaps never had the mycorrhizal fungi necessary for trees to survive there.

Mushroom of the Month, February 2010

Only a minority of fungi from the phylum Ascomycota produce large and conspicuous fruitbodies, but among them are some tough (fun)guys that can be found all through the year. This month's mushroom (well, fungal fruitbody might be more appropriate) is candle-snuff fungus, and it is easy to find in winter when dead wood on the forest floor is not hidden by long grass, bracken or other tall vegetation.

Xylaria hypoxylon belongs to a group of fungi known as the Pyrenomycetes (meaning 'fire fungi' - a reference to their blackened and burnt appearance). The generic name comes from the same Greek word xýlon (as does xylem - wood, in the sense of the tough cellular material that forms the roots, trunk and branches of trees). The specific epithet hypoxylon is yet another reference to wood, and with the prefix 'hypo' usually meaning below or under, but in this case perhaps 'reduced', since this fungus is able to consume timber whose cellulose and hemicellulose (the softer material) have already been fairly comprehensively broken down by other fungi, for example sulphur tufts or honey fungus. Any other suggestions?

One question I have never been asked in respect of candle-snuff fungus is 'are they edible?' Even if they were, why would anyone want to waste time on collecting them when there are plenty of really good edible fungi available throughout the year?

Xylaria fungi (and there are plenty of other species in the genus, including Xylaria polymorpha, commonly called dead man's fingers) are able to reproduce sexually and asexually. In the case of the candle-snuff fungus, the antler-like fruitbodies, or 'stroma' to use the technical term, are black at the base of each stem and almost white further up and along the branches, which are the places where the asexual spores (conidia) are produced - but you will need a high-power microscope to see these features. This fungus also produces sexual spores from asci that develop on the inner walls of vessels called perithecia, which are embedded in the surface of the stroma, and if you cut across a fruitbody and look at the section under a strong hand lens or a low-powered microscope these vase-like perithecia are easy to see.

That's what I find about most Ascomycetes: they are only of passing interest... until you look more closely and then they are quite fascinating in their structures and habits.

Mushroom of the Month - January 2010

Winter is not the best time for cap-and-stem fungi, but if we get a mild spell there is a group of fungi ready to spring forth in woodland - the Cortinarius mushrooms. I am using the term 'mushrooms' in the broadest sense rather than in its narrow 'edible-fungi' interpretation, because many Cortinarius species are known to be poisonous - some of them deadly - and nearly all others are of dubious or unknown edibility. For that reason the total number of Cortinarius species that I can recommend for eating is... zero. These are look-at-me mushrooms, and not feast-on-me fungi.

Cortinarius cinnamomeus is a wonderful winter woodland species, as it generally appears quite late in the autumn and often fruits through the New Year and occasionally into February. It's also a very distinctive mushroom, unlike most species in this difficult group.

In the UK I find this gregarious mushroom most often in coniferous woodland, but it is also found under birches in dry heaths. All Cortinarius fungi are mycorrhizal (they form symbiotic associations with the roots of trees), so they do not occur in grassland (at least not significantly beyond the point where tree roots extend into the fields).

For identification details see the fungi section of http://www.first-nature.com/ where this and several related species are pictured and described.

Here's another picture of Cortinarius cinnamomeus:

One final point about winter mushrooms... after heavy frost it's generally a week or ten days before any new fruitbodies emerge from the forest floor, but some of the wood rotters and parasites that grow on trunks and branches cope much better with the cold.

Happy New Year, and happy fungi hunting!

Mushroom of the Month - December 2009

This month's mushroom is an alien. Clathrus ruber looks alien and it doesn't really belong here, having arrived fairly recently, so experts believe. But here it is and it seems determined to stay; and, with the climate becoming ever more favourable to it, this mainly Mediterranean species is likely to be seen ever more frequently in the British Isles. Already it is fairly common in some southern parts of England (most particularly in the Westcountry and on the Isle of Wight) but also in southern Ireland too. In the Channel Islands these striking fungi are now very often a decorative feature of compost heaps and grassy orchards. That said, you can count yourself lucky if you do come across this remarkable relative of the stinkhorns... unless you happen to sit on one accidentally. If you think the common stinkhorn (Phallus impudicus) is smelly, save the superlatives for this rotter! For close-up photography a scuba outfit would be a good investment.

In much the same way that setting out to find giant puffballs is pretty much a futile quest (unless you already know a site where they occur), so seeking the cage fungus is also something best suited to masochists; these are fungi you just come across once in a (very long) while. The one pictured below was spotted in a shallow, leaf-litter filled ditch in the Serra around Monchique, in southern Portugal. They are not common there, but we did manage to find three in one day.

The half-buried 'eggs' from which the cage fungi emerge look very much like those of the common stinkhorn, but as the time nears for an almost explosive emergence the outer skin ruptures and the embryonic cage is clearly visible - see below.

The eggs are typically 3cm in diameter, but when fully expanded the cage is three times that size, with dark olive-green gleba coating the inner surface. Flies love them, of course, attracted to their stench of rotting meat, and the short-lived fruitbodies last just one or two days before collapsing and turning to mush.

Also known as the latticework fungus, Clathrus ruber occurs in summer and autumn, but with the heat emitted by rotting compost or wood chippings they can even be found in November unless the weather turns icy cold. Like us, they are not at all keen on frost.

If you know someone whose garden is infested with these amazing fungi, that's the place to go to see them... But take a clothes peg for your nose, and just be glad that it's not your garden!

There are more pictures and information about this mushroom (and its darker red relative Clathrus archeri) on www.first-nature.com/fungi - and we wish you much happy fungi foraying throughout the forthcoming festive season.