Saturday, November 2, 2013

Neighborhood Mushroom Watch (Someone’s Got To Do It): Part II – A Summer Sampler

Mushrooms and toadstools. Mold and mildew. Puffballs and earthballs. Jellies and slime. Rusts and smuts. Stinkhorns and bloodfoots. The only thing more colorful than their names is their staggering diversity and bizarre biologies. This post is a continuation of the mycological mission I initiated in Part I (here), in which I discussed the lifecycle of the mushroom. In this final fungi post, I document some of the more remarkable specimens sprouting in my yard and down the street.
Amanita muscaria var. guessowii
“Esteemed by both maggots and mystics” (David Arora), this hemispherical-shaped, yellow-capped, conifer-loving beauty is known as the American Eastern Yellow Fly Agaric. The “fly” designation, according to one source, refers to its use in Eastern Europe as an insecticide, supposedly lethal to flies when mixed with milk.

The warts on the cap’s surface are remnants of the “universal veil”
that shrouded the juvenile mushroom as it germinated through the soil.

Amanita is a study in contradictions. While some are wildly hallucinogenic and delicious beyond compare, a few are the most toxic of all mushrooms with names such Death Cap and Destroying Angel. After the ingestion of a toxic Amanita, it can take a few days for symptoms to appear, which is particularly dangerous since its toxins insidiously demolish one’s kidneys and liver.

In his memoires, Voltaire recounted Holy Roman Emperor Charles VI’s death from eating sautéed amanita as, “The dish of mushrooms that changed the destiny of Europe.” Because amanita resembles several other edible species, fungiphile and author Arora warns, “When in doubt, throw it out.”

Of the 16,000 species of mushrooms identified by mycologists, the red and white-spotted fly agaric
is the iconic mushroom. It's often referred to as a toadstool due to its poisonous and psychoactive properties.

Omphalotus illudens
Like an annual time clock during the second week of August, dense clusters of bright orange mushrooms appear at the foot of an aging oak down the street. With the same regularity, my neighbor frustratingly digs up the crop in hopes of eradicating it, only to see it return the following year. Picking apples in an attempt to eradicate the tree is futile. As long as the "rooted" mycelium remains viable within the soil, the fungus will continue to spawn new mushrooms.

Mushrooms are fruiting through a crack in the sidewalk where the tree’s roots have barely broken the surface.

Omphalotus is also known as the Jack O’Lantern mushroom likely due to its pumpkin-color, although some sources attribute the name to its eerie property of neon-green bioluminescence. About 90 species of fungi glow in the dark along with certain bacteria, algae, marine creatures and insects such as the familiar firefly. Anyone can observe it in a forest on a dark summer’s night, although I’ve failed to photograph the phenomenon in my dark basement three years running.


Some references state that bioluminosity occurs at all stages of the fungi’s lifecycle, while others indicate that it only occurs in fresh specimens in which spores are still forming, so timing is critical. Light-emission is the result of oxidation involving an enzyme called luciferase. One theory is that insects receptive to the emissions are attracted to the luminescence, which assists in spore dispersal.

The mushroom caps start out flat but become centrally depressed, eventually becoming wavy and lobed.

Omphalotus is frequently mistaken for its lookalike, the prized chanterelle mushroom Cantharellus, a $1.5 billion global market, hence its occasional reference as False Chanterelle. The similarity is potentially hazardous, since chanterelles are highly edible and our Jack O’Lantern is deadly poisonous. Muscarine, its neurotoxin, produces GI symptoms, visual disturbances, irregular pulse and respiratory failure.

In Polish, there’s a phrase, "A sapper (field soldier) and a mushroom collector make a mistake only once." In spite of its toxicity, Irofulven, a chemically modified version of the mushroom’s toxin, is currently undergoing clinical trials as an anti-tumor agent.

Coprinus plicata
With a delicate, pleated cap, many of the Coprinus mushrooms are extremely ephemeral, often lasting only a few hours in the morning. The reason is that its gills autolyse (self-digest) and deliquesce (turn to liquid) at maturity into a black, inky fluid that drips to the ground, hence their common name of Inky Caps. Autodigestion is a unique method of spore dispersal. As the spores at the mushroom’s periphery ripen first, the release of enzymes causes the cap to curl back spreading the gills and discharging the spores into the air. What’s left is a ragged stalk.

The autodigestive-spore releasing process is recalled in Shelley’s memorable lines of The Sensitive Plant:

“Their mass rotted off them, flake by flake
Till the thick stalk stuck like a murderer’s stake;
Where rags of loose flesh yet tremble on high,
Infecting the winds that wander by.”

Ionotus tomentosus
This leathery bracket fungus is primarily a pathogen of spruce forests but also infects other evergreens. It was fruiting in my back yard at the base of a tall, old spruce. It’s frequently associated with infections of tree roots and their mortality. Last year, I cut down two nearby spruces and wonder if this one will be next. The fungus is often associated with spruce beetles.

It’s a member of phylum Basidiomycota (see post Part I here), but rather than gills, its spores are produced within tiny, circular tubes that line the undersurface of the fruitbody. That gives the surface a perforated appearance, hence the fungi’s alternate name of polypore.  

Ganoderma applanatum 
In New England, it’s very common to find massive, slow-growing, beeches on the grounds of stately old homes, churches and cemeteries, planted for their dense shade and botanical grandeur. For years, this thin-barked beech up the street began to host an array of huge bracket fungi on its south-facing side. Passersby couldn’t resist stopping for a look. I took the presence of the fungi as an indication of ill health. Sadly, this summer the majestic tree suddenly became leafless and was cut down. It left a huge void both on the ground and amongst the canopy of the surrounding trees.

Appearing somewhat near the base of the tree, the polypore is gray to brown in color, and often green with algae. They are also called Artists’ Conks since lasting pictures can be carved onto their undersurface. When they fruit on live trees, they are often parasitic and allow insects and woodpeckers to invade the bark.

Its layers are an indication of its age. A large specimen can liberate up to 30 billion spores a day for 6 months of the year. Multiply that by its age of about 10 years for the polypore seen below! High spore production illustrates the mathematics of survival, since most spores fall upon a nutritionless, hostile substrate.

Fomitopsis pinicola
Like Ganoderma, this Red-Banded polypore is a common, perennial bracket fungus that was boldly attached to another spruce in my back yard. Its concentrically grooved bands of yellow to orange and red, its thick pizza crust margin, and its resin-coated surface make it both hard to miss and misidentify. Its preference is dead wood (conifers in particular), rotting logs and stumps rather than live trees.

Scleroderma citrinum
This Earthball, along with related puffballs, earthstars, bird’s nest fungi and stinkhorns, produces its spores inside the fruitbody rather than on the undersurface of mushrooms. At maturity, the fruitbody ruptures, such as during a rain, exposing a purple-brown spore-mass, freeing the spores to inoculate the wind. Unlike puffballs that develop an aperture through which the spores escape, earthballs break up to release their bounty.

This spherical yellow-brown Earthball with its ornately decorated, raised mosaic pattern was fruiting in the woods in my neighborhood. They’re all classified as Gasteromycetes or “stomach fungi.”

Fusicolla merismoides (possibly)
Also in the woods, this amoeba-like slime mold appeared after a soaking summer rain. The gelatinous oozing, vomitous blob looked like something out of a B-movie. Slime molds (mould is the British version) produce spores and thus were formerly classified as Fungi, but many taxonomists consider them as protists (see post Part I for a taxonomic explanation here). Since mycologists traditionally group and discuss them with fungi, so have I, especially since they appeared along with the mushrooms this summer.

Typically found on soil, lawns, mulch and on the forest floor where shady and damp, they can travel several feet and climb any object to feed on microorganisms that live on dead plant material such as bacteria and fungi, and contribute to its decomposition. The slime searches for a host, surrounds it, and then secretes enzymes to digest it. Protoplasm at the cell’s periphery creates a type of movement called “shuttle streaming.”

Slime molds, while brainless, are smarter than they look. Amazingly, some are capable of navigating and solving an agar maze in search of food. This display of “intelligence” occurs by anticipating thermal changes at predictable time intervals. When it’s time to fruit they even migrate to a more desirable site for spore dispersal, often quickly at night to minimize the risk of dehydration. Despite being a single cell, each part of the plasmodium reacts to environmental information independently. By combining the reactions, the mass responds without even a conscious thought. “Nothing can stop it!”


Fuligo septica
The yellowish, bile-colored Dog Vomit (or Scrambled Egg) slime mold was believed to be used by witches to spoil their neighbors’ milk. I found this specimen hiding under a rotting log in a nearby woods. Like the slime above, the amoeboid mass migrates in search of nutrients. Under adverse conditions such as dryness or cold temperatures, the slime can form a hardened, resistant structure called a sclerotium, which is capable of reforming and reinitiating its protoplasmic exploitations.

Its yellow pigment, fuligorubin A, chelates metals and converts then into inactive forms, which accounts for the slimes high resistance to toxic levels of metals (up to 20,000 ppm). The pigment is also thought to be involved in photoreception for purposes of energy. Not that you’re tempted, but it’s inedible.

Genus Ramaria (possibly)
Another member of phylum Basidiomycota, coral fungi come in many colors, and many are tasty. The fruitbody is densely branched and fruits on the ground in woods. Although related to mushrooms and not the marine animal for which they resemble, corals bear no anatomical likeness to mushrooms. But like the undersurface of mushrooms’ caps, their many branches provide a high surface area for the basidia, the spore-producing structure of the fungus, similar to mushroom’s gills, pores, teeth and folds (see Part I).

There are many forms of coral fungi, originally lumped into one unwieldy genus. Now there are over 30 genera, looking coral-like due to convergent evolution.

My “Neighborhood Fungus Watch” wouldn’t be complete without mention of the ubiquitous gray-green rosettes on trees, tangled masses of hair suspended from branches, miniature goblets on the ground and yellow-orange crusts on rocks. Lichens are neither plants nor single organisms but are “miniature ecosystems” (Hinds). 

They are a partnership of two, and sometimes three, lifeforms that coexist as one for their mutual benefit. It’s a symbiotic association between a species of fungus (the mycobiont) and a species of photosynthetic algae (a photobiont, usually Trebouxia).

The algal component is either eukaryotic green algae or prokaryotic blue-green algae (explained in Part I). With over 14,000 species to date, lichens are classified within Kingdom Fungi based on the Latin name of the fungal partner (which is usually an Ascomycota or “cup” fungi), since the relationship is largely fungal (90%). Therefore, lichens are often referred to as “lichenized” fungi. Most of the vegetative body of the lichen, called the thallus, is formed by the fungus.

The algal component lives not within the actual cells of the fungus but sandwiched within the body of the fungus (the medulla) between the upper and lower fungal cortex. Anastomosing hyphae form a loosely arranged network that are in communication with the algal cells. Strands of root-like hyphae (rhizines) attach the lichen to the substrate.

Schematic cross section through the thallus (body) of a flat, leaf-like (foliose) lichen.

The algal member provides energy to the fungus in the form of manufactured simple carbs such as glucose or sorbitol. In return, the alga gets a happy home with a favorable microenvironment from desiccation, protection from excessive UV radiation and mineral nutrients from the attachment-substrate and the atmosphere. Most vascular plants would be incapable of populating the lichen’s exposed, inhospitable, nutrient-poor habitats.

Therein lies the enigma of lichens! They are the hardiest of “plants” capable of surviving arctic cold, desert heat and extreme drought. In a 2005 test, lichens even survived 15 days of exposure to the vacuum of space on a Russian rocket. Yet, they are incredibly sensitive to pollution since they absorb water and nutrients from the air. Devoid of lichens, industrial regions of the world are referred to as “lichen deserts.” In my nearby Boston, you don’t start seeing lichen-covered rock walls until several miles from the city until reaching the “clean air” of the suburbs. Thus, lichens are bio-indicators of air quality. There's even a profound association between lichen presence and a reduced risk of lung cancer. Another reason to look down at the ground!

Lichens are divided into groups or growth forms based on modes of substrate attachment. The three most common are: crustose (crust-like), foliose (leaf-like) and fruticose (long and hairy often with cups).

Evernia prunastri is an antler-like fruticose (hairy), “oakmoss” lichen that favors growth on decaying oak.
They are commercially harvested in Europe and sent to France for their fragrant compounds used in perfumes.
Typically growing on bare, exposed rock especially at high elevations, this mosaic of Rhizocarpon geographicum is a crustose (crust-like) “map” lichen that is tightly adherent to the rock substrate and even within the substrate. Several species of crustose lichens often occur together on the same substrate. Lichenometry is used by climatologists to date rockslides and glacial deposits such as moraine systems based upon their slow growth rate. 
Flavoparmelia caperata is a foliose (leaf-like), “common greenshield” lichen on a tree. Powdered forms have been used to treat burns in Mexico. Native Americans have used similar forms for dyes. The basic pattern of growth for lichens is to expand centripetally from the point of origination. This gives the thallus a rounded appearance and allows an estimation of the rate of its growth. Like rocks that exhibit appreciable differences in their physical and chemical properties, the barks of trees have varying textures, moisture-carrying capacities and chemistires such as pH. Thus, lichens show specificities as to their preferential substrates.

 Amazing lichen facts that your friends probably don’t know:
1.) Lichen symbiosis may have been one of the first steps in the colonization of land. In the Precambrian, lichens may have lowered CO2 levels sufficiently to plunge the Earth into global glaciation typified by Snowball Earth between 750-580 Mya. Their eventual terrestrial colonization may have raised the atmospheric O2 levels enough to permit the Cambrian Explosion.
2.) Lichens can physically weather a granite substrate by penetrating intergranular surface boundaries, voids and cleavage planes. The swelling and contraction of hyphae can then break up the rock. They can chemically weather granite by leaching out potassium and iron. On calcareous (limestone) rocks, lichens produce weak acids that dissolve the substrate.
3.) Beatrix Potter, the celebrated author of Peter Rabbit fame, was a pioneering mycologist who studied and experimented with fungus germination under the microscope as early as 1887. She published Les Champignons on fungus and lichens with over 65 original, watercolor drawings. Her scientific fungal paper was read by a male colleague before the men-only Linnaean Society of London, but it was rejected from publication because of her gender. Fortunately for children everywhere, her artistic talents found creativity elsewhere.
4.)  Fungi and algae, although capable of forming an intimate partnership, are totally unrelated phylogenetically. Fungi and humans share a common ancestor and are more closely related. One would expect that all lichens are more closely related than they would be to other fungi. Instead, the lichen partnership has evolved a myriad of times, because the DNA and genes of different lichen species are more closely related to non-lichen fungi than they are to other lichen. (Gargas et al, Multiple origins of lichen symbiosis in fungi suggested by SSU rDNA phylogeny. Science 268: 1492-1495, 1995).

Nudgers and shovers
In spite of ourselves.
Our kind multiplies:
We shall by morning
Inherit the earth.
Our foot’s in the door.
Mushrooms in The Collected Poems by S. Plath, 1959

With great appreciation, I thank professional mycologist Taylor Lockwood and amateur “mushroom expert” Michael Kuo for their expertise in identifying many of the more obscure mushrooms in my neighborhood. Their respective links are below.

Kingdom Fungi by Steven L. Stephenson
Macrolichens of New England by James W. and Patricia L. Hinds
Mushroom by Nicholas P. Money
Mushrooms Demystified by David Arora
Mushrooms of Northeast North America by George Barron
Mushrooms, Simon and Schuster’s Guide by Gary H. Lincoff

Tom Volk here

Michael Kuo here
Michael Wood here
Taylor Lockwood here
North American Mycological Association here


  1. I've enjoyed these two posts very much -- great review for one thing (30 years since my mycology course). And fungi are truly fascinating. I hope this isn't really your "final fungi post"

    1. Hollis, You always make me smile with your kind words! This will be my "final" fungal post until the new crop sprouts in 2014. Thank you!

  2. Although you won't realize this Jack, i do share your posts on various Google+ science community groups and have gotten some great feedback. Anyway, just wanted you to know that and great articles as always

    1. Kevin, Thanks for the good words and sharing my posts with the science community! Very much appreciated! Jack