Cornell Mushroom Blog 2014-10-21T14:25:59Z Cornell Blogs Service Student X <![CDATA[Hope for Impatiens]]> 2014-09-10T00:54:33Z 2014-09-10T00:54:33Z A post by Megan Daniels, a talented mycology grad student at Cornell.

This year Grandma couldn’t find impatiens (Impatiens walleriana) to plant in her flower beds. She’s always planted impatiens! But lately, impatiens have been sickened by downy mildew, caused by Plasmopara obducens. This plant disease has received attention the past few years because it decimates the most popular varieties of this annual garden plant. What you probably haven’t heard yet is the story of how impatiens, through sex, sheer luck, and the attention of one man, rose to the pinnacle of popularity only to be suddenly destroyed, all thanks to an unassuming downy mildew that has been lurking close to our back yards.

Before and after, by M. Daughtrey

The story begins on shady river banks of east Africa, where cultivated impatiens have wild relatives. Compared to their domesticated descendants, wild impatiens are small, spindly, and have fewer flowers. They are unique in the way they disperse their seeds, using spring-loaded seed pods triggered by the slightest touch. Almost a century ago, impatiens were introduced as ornamentals to South and Central America, where their seed flinging habit allowed them to escape gardens and become naturalized.

It was these rogue impatiens, growing on a shaded Costa Rican roadside, that captured the attention of one Mr. Claude Hope. It’s an understatement to say Hope had a green thumb. A Texan by birth, he was a brilliant horticulturist who worked for the US government during World War II, researching plants in Central America. Much later he recalled in an interview that he’d first noticed cheerful impatiens on his walk to work during those years. Something about that plant, hardly more than a weed, inspired him. He recognized impatiens’ potential to become a popular garden plant. After the war, he put down roots in Costa Rica, developed a successful seed company, and began breeding impatiens, shaping them into the popular plants we know today.

impatiens downy mildew, by M. DaughtreyPlant breeding is a discipline at the intersection of gardening and genetics. Every vegetable on a grocery shelf, and every packet of seeds is a product of this process. It’s a sexy science, beginning when two plants are intentionally crossed. Their best offspring are selected for favorable traits by breeders and interbred over multiple generations, which might take years or decades. Once ideal plants are produced, they are usually only crossbred with each other, or clonally propagated with cuttings. Maintained this way, plants keep producing offspring with the desired physical traits. The impatiens varieties Claude Hope bred had more and longer-lasting blooms, in a range of bright colors. They were shade-tolerant and perfectly suited for North America’s gardening appetite.

Most impatiens planted today owe their existence to the Father of impatiens’ six year-long breeding effort. For decades impatiens have been a garden staple, but recently this plant breeding success story took a dark twist. Hope considered himself extremely lucky for the relatively short time it took to create what became the most popular annual plant in America. But the same gardens, window boxes, and parks that he helped transform face a serious threat today. Mr. Hope died in 2000, and did not live long enough to witness their devastation by downy mildew.

Impatiens downy mildew is caused by Plasmopara obducens, which is not a fungus but an oomycete, a group better known as water molds. They resemble fungi to the naked eye, but their closest evolutionary relatives are diatoms and brown algae. Other oomycetes are also plant pathogens, and some cause sweeping epidemics and crop losses. One infamous example, Phytophthora infestans, caused Ireland’s Great Potato Famine in the 1840s and remains an important disease of potatoes and tomatoes today.

Impatiens downy mildew infects a range of impatiens varieties, but most of the time infections are not fatal. It’s just bad luck that it is truly devastating when it infects the most popular kinds of impatiens– hybrids developed by Mr. Hope from Impatiens walleriana. When these plants are infected they go from mild symptoms, with fuzzy white mildew on the undersides of leaves, to complete defoliation in the blink of an eye. Symptoms are less dramatic on other impatiens varieties– maybe only a little yellowing of leaves and stunted growth.

Here’s a time lapse of impatiens being killed by downy mildew.

Downy mildew sprouts on the underside of leaves as a fuzzy grey carpet, making millions of spores that are spread by rain and wind to other susceptible plants. When a spore lands, it can infect by growing directly into a leaf, or by producing swimming spores (zoospores). Zoospores swim across plant surfaces in thin layers of dew or rain, initiating multiple points of infection. A third kind of tough, thick-walled spore (the oospore) can endure in soil, perhaps for years, waiting for a susceptible plant to infect.

Unlike some pathogens that have been introduced and cause problems in a new environment, impatiens downy mildew is native to North America. It’s been documented here since the 19th century infecting pale jewelweeds and spotted touch-me-nots, native relatives of Impatiens walleriana. On these native hosts, symptoms are mild, sometimes little more than purple leaf spots. We have evidence of downy mildew infecting wild impatiens going back at least a hundred years. Impatiens have been popular for over thirty years, so why has this downy mildew become a problem in nurseries and gardens only in the past several years?

The factors behind the epidemic are under study by plant pathologists, while plant breeders search for disease-resistant varieties. We don’t know for sure, but we can guess that a random genetic change gave one lucky spore of our native downy mildew a new ability to kill Impatiens walleriana. The lucky descendents of this lucky spore found themselves surrounded by genetically similar, and thus similarly vulnerable Hope hybrids. This new downy mildew variant took off like wild fire. This is evolution in action. Luckily, not all impatiens varieties are vulnerable to downy mildew. For now Grandma can switch to New Guinea impatiens, or one of a handful of new, resistant impatiens varieties.

References and further reading:

Images courtesy Margery Daughtrey. Thanks, Margie!

Kathie Hodge <![CDATA[Twinkly earthstars]]> 2014-06-03T19:29:34Z 2014-06-03T19:29:34Z A post from your editor, Kathie Hodge, who’s fascinated by fungi that move.

Aside: Recently I learned that the Library of Congress has added this blog to their historical collection of Science Blogs. I think that’s pretty cool. Thanks for coming along on the ride.

Fungi are lively things, but (like this blog) you can seldom spot them moving. That’s why we like time lapse videos here on the Cornell Mushroom Blog, to hurry things along a bit. Our fungus of the day barely needs speeding up — pleasingly, it’ll do its thing while I share a cup of tea with visitors at my lab table. Drop one in water and in ten minutes it unfolds, revealing a plump center that you can puff with a poke. As it dries, it slowly closes up, ready for teatime tomorrow. A small wonder.

There are two kinds of earthstars that look similar only because they’ve hit upon the same delightful solution for spore dispersal. This one, Astraeus, has the infinite ability to open and close, open and close. Species of Geastrum look like kin, but do their trick just once and remain open for business. Whereas Astraeus earthstars are the sisters of boletes, Geastrum earthstars are relatives of stinkhorns.

I found my Astraeus earthstars among the dunes of Cape Cod, Massachusetts. Then in my local Asian grocery, I found a bright red can from Thailand, marked “Astraeus hygrometricus,” and here you see a photo of its contents in my palm. Astraeus earthstars are a valuable wild mushroom in Thailand, and are picked before they even open up, then sold both fresh and canned. But I’ve never heard of anyone gathering earthstars for dinner here in North America, and it made me wonder.

edible earthstars from ThailandUnlike you, perhaps, I didn’t wonder about what recipe to use for my Cape Cod earthstars (well past their prime; already open and full of powdery spores). No, I wondered what we mycologists often wonder — are those Thai earthstars really the same thing as these American ones? And, not surprisingly, I found that the answer is: No, they are not. So I don’t plan to cook up any American earthstars, because I don’t know whether they are edible. Just because they are in the same genus doesn’t mean they should be (think, Amanita phalloides (deadly) vs. Amanita caesaria (yummy)).

For the longest time, we thought all Astraeus earthstars were the same species, and we called them all Astraeus hygrometricus (the water-measurer; the barometer earthstar). But the littlest thing in biology, under scrutiny, often turns up surprises and intrigues. That’s what Phosri and friends found,2 when a closer look revealed that there are many different lineages of earthstars, and they had to describe some new species to accommodate them all. So now we know that my Cape Cod earthstars are quite different from those you’d eat in Thailand, in both their habitat and their genetic make-up.

A can of Thai starsWhen something you thought you knew needs dividing into many pieces, there’s bound to be issues with names. Practically every Astraeus collected over the last two centuries has been called A. hygrometricus. Now we know most of them are not, which means that only some of the things we thought we knew about this species are actually true. The real Astraeus hygrometricus occurs in France and Turkey. My can of “A. hygrometricus” from Thailand is one of the two Thai species: A. asiaticus or A. odoratus. And what shall we call our American species?

American Astraeus earthstars, so far, seem to be either A. morganii (like mine– plumpish; spores not too bumpy) or A. smithii (littler; warty spores), and I’d bet there are other species too, awaiting discerning eyes. I can sense you groaning at this proliferation of names… but don’t. You don’t need to know the names of every little thing — you can just call them Astraeus if you like, or barometer earthstars. But WE need to have names for every little thing. Not having names for things makes them almost impossible to perceive. They’re genetically different, and they’re probably ecologically quite different in ways we’ve never noticed. Without good names it’s hard to answer important questions like “is it edible?” and “what’s it doing?”

What IS it doing, anyway? Sand seems an improbable place to find fungi. You’ll be pleased to hear that under the shifting sands my Cape Cod earthstars are hooked up to the roots of dune plants, forming friendly relationships (ectomycorrhizae!) that benefit both plant and fungus. Their starry fruits and clever dispersal mechanism help them spread spores that find new seedlings to team up with; new dunes to stabilize.


  1. C. Phosri, R. Watling, M.P. Martín, J.S. Whalley. 2004. The 

genus Astraeus 


Thailand. Mycotaxon 89(2): 453-463.
  2. C. Phosri, M.P. Martín, Roy Watling. Astraeus: hidden dimensions. IMA Fungus 4(2): 347–356. doi:10.5598/imafungus.2013.04.02.13 [use this article to ID your earthstars]

Thanks to Claire Smith for the time lapse video and earthstar photography. Thanks to Lawrence Millman for the good company.

Kathie Hodge <![CDATA[Ladybug Fungi]]> 2014-02-11T12:38:20Z 2014-01-17T18:16:19Z A post by Cornell grad student and mycology maven Megan Daniels.

I promise we will get to fungi, but first, let’s talk about ladybugs. There’s a new ladybug in town, and it’s not as charming and adorable as our old favorites. It’s the Multicolored Asian Ladybug, Harmonia axyridis. They were introduced to North America in the 20th century to eat pesky aphids: one ladybug can eat 200 aphids a day. This is really their most charming characteristic— their other attributes make them undesirable invasive insects (Koch 2003). They appear to be displacing friendlier native species (check out the Lost Ladybug Project). They have also become household pests, since they overwinter in huge aggregations on or in our houses. If you have them in your home this winter you know that if you piss them off, they produce a foul stink known as “ladybug taint.” If you’re a winemaker, ladybug taint can ruin a whole batch of wine if you accidentally squash some ladybugs along with your grapes. Even in low numbers they give wine the taste of rancid peanuts or rotten peas (Mansell 2009). Worse, ladybug allergy (that’s right, ladybug allergy!) is increasingly a problem for humans whose houses are ladybug overwintering sites (Goetz 2009). No laughing matter, and to top it all off, they sometimes bite. They’re just not very nice ladybugs.

Hesperomyces virescens, by Claire SmithSo, on to fungi. Today I present three: one friend of ladybugs; one foe; one just a nuisance. The nuisance is the coolest: Ladybugs don’t get fleas— but these labouls are the closest thing. They are blood-sipping parasites that form small colonies on the backs and bellies of ladybugs. With the naked eye they can be mistaken for plant pollen. Mordecai Cubitt Cooke, an early popularizer of fungi, dubbed them “Beetle Hangers” for their weird hook- or club-like appearance (Cooke 1892).

Beetle hangers belong to a diverse and surprisingly host-specific group of fungi, the Laboulbeniales. Of the 2000 described species an impressive 80% parasitize beetles, and many live only on a particular species of beetle. One of the first descriptions of this group was by Harvard’s Dr. Roland Thaxter. He did foundational work on the group, writing and illustrating a goliath five part series titled Contribution towards a monograph of the Laboulbeniaceae. Among the descriptions and illustrations that make up this work is Hesperomyces virescens, the green beetle hanger, which infects a variety of ladybugs.

A green beetle hanger’s entire life cycle takes place on a ladybug. The hard exoskeleton of insects seems unwelcoming, but beetle hangers are well suited for it. The life cycle begins with a spore that gets stuck to a ladybug. First the bottom cell of the spore, which will become the “foot,” grows until it penetrates the body of its host by creating a small gasket-like hole called an “o-ring” (Weir and Beakes 1996). Once inside, it grows a branched structure to absorb nutrients, like the roots of a tree. Its growth inside the ladybug is limited and causes little harm. Once the foot is firmly planted, the upper part of the spore grows to form male and female structures that allow it to reproduce. Ascospores made after fertilization are ejected by a trigger mechanism when touched— BANG! That’s how beetle hanger spores are spread among ladybugs, or to new parts of the same ladybug (Weir and Beakes 1996, Brodie 1978).

Thaxter drawing of Hesperomyces virescens
The green beetle hanger takes advantage of ladybugs’ gregarious and promiscuous behavior to get around. Female ladybugs can spread infection during matings with different males, and vice versa. Even encounters with infested deceased ladybugs can spread the fungus. Green beetle hangers spread easily among ladybugs overwintering in groups—infection can increase by as much as 40% (Nalepa and Weir 2007, Weir and Beakes 1996). Yet despite the probable discomfort and sometimes impairments to movement, most infected ladybugs lead full and happy lives (Weir and Beakes 1996, Brodie 1978).

While green beetle hangers may be irritating but harmless to ladybugs, another fungus of multicolored Asian ladybugs is actually beneficial. Multicolored Asian ladybugs are typically infected by parasitic fungi called microsporidia. Normally, microsporidia are disease organisms, but scientists were baffled to find them abundant in ladybug blood, causing no negative health impacts. On the contrary, it turns out they are a ladybug’s secret weapon: when native ladybugs eat microsporidia-infected eggs of multicolored Asian ladybugs they are essentially poisoned. The microsporidia may even be behind the antibacterial activity of their blood (Vilcinskas et. al 2013). By helping to eliminate native competitors these microsporidia contribute to their hosts’ success in taking over the world (Williams 2013, Vilcinskas et. al 2013).

Microsporidia are microscopic single-celled fungi. They are thought to have an ancient origin. Although microsporidia are widespread in animals and especially insects, with over 1200 known species, they are generally not good for health. For example, in immune compromised humans they cause a chronic disease called microsporidiosis. Incapable of reproducing outside of a host’s cells, they survive and are transmitted from cell to cell and animal to animal as egg-shaped spores. Once a spore makes contact with a host cell a long tube is ejected. It acts like a syringe to inject the microsporidium into its host. Once inside a host cell exploits its hosts cell machinery to make copies of itself, producing new spores that repeat the cycle.

Beauveria by Alan RockefellerNow we’ve met a nuisance fungus and a helpful bioweapon, but every story needs a villain. If you’re sick of ladybugs getting into your wine and your house, here’s a fungus to kill them. Beauveria is a genus of molds that kills bugs. Various strains of Beauveria have been developed as biological controls of pest insects. Maybe we can find a strain perfect for killing off ladybugs who’ve overstayed their welcome, as Roy and colleagues (2008) suggest. These fungi don’t have to be injected or “inhaled,” they have the ability to drill their way into a ladybug and eat its insides (luckily they don’t eat me or you). Then they burst gloriously forth and grow the deceased ladybug a fuzzy white jacket.

One ladybug: three different fungi, each adapted to live with its host in a different way. You can see why we think the world of insects will be a great place to discover a lot of fungal diversity.

For more green beetle hangers, visit their page on BugGuide.

Image Credits: Thanks to Claire Smith for the ladybug belly; Roland Thaxter for the green beetle hanger drawings; Alan Rockefeller for the Beauveria-swaddled ladybug.


  • Brodie, Harold J. (1978) Fungi, delight of curiosity. University of Toronto Press.
  • Cooke, M.C. (1892) Vegetable wasps and plant worms: a popular history of entomogenous fungi, or fungi parasitic upon insects. Society for Promoting Christian Knowledge, 364p.
  • Goetz, David W. 2009. Seasonal inhalant insect allergy: Harmonia axyridis ladybug. Current Opinion in Allergy and Clinical Immunology 9(4): 329–333. DOI: 10.1097/ACI.0b013e32832d5173
  • Koch, R.L. (2003) The multicolored Asian lady beetle, Harmonia axyridis: A review of its biology, uses in biological control, and non-target impacts. Journal of Insect Science 3:32.
  • Mansell, T. (2009) A rare and interesting wine fault: Ladybug taint. New York Cork Report.
  • Nalepa, C.A. and A. Weir (2007) Infection of Harmonia axyridis (Coleoptera: Coccinellidae) by Hesperomyces virescens (Ascomycetes: Labouleniales): Role of mating status and aggregation behavior. Journal of Invertebrate Pathology. 94, 196-203.
  • Roy, H.E., P.M.J. Brown, P. Rothery, R.L. Ware and M.E.N. Majerus (2008). Interactions between the fungal pathogen Beauveria bassiana and three species of coccinellid: Harmonia axyridis, Coccinella septempunctata and Adalia bipunctata. BioControl 53 (1): 265–276. doi:10.1007/s10526-007-9122-0
  • R. Thaxter (1896). Contribution towards a monograph of the Laboulbeniaceae. I. Memoirs of the American Academy of Arts and Sciences 12: 187-429.
  • Vilcinskas, A., K. Stoecker, H. Schmidtberg, C.R. Roehrich, and H. Vogel (2013) Invasive harlequin ladybird carries biological weapons against native competitors. Science (Washington D C), 340(6134), 862-863.
  • Weir, A. and G.W. Beakes (1996) Correlative light- and scanning electron microscope studies on the developmental morphology of Hesperomyces virescens. Mycologia, 88(5), 677-693.
  • Williams, R. (2013) Ladybird bioterrorists, the Asian harlequin ladybird carries a biological weapon to wipe out competing species. The Scientist.
Kathie Hodge <![CDATA[A deadly Russula]]> 2014-01-29T01:51:54Z 2013-12-30T04:25:32Z A post by my talented student Ben Hoffman, who took my Mushrooms class in 2013.

An entertaining way to confirm a mushroom is a Russula is to throw it at something (a tree, the ground, a friend) and watch for its explosion into little pieces. This is satisfying because it confirms the brittle nature of the mushroom while at the same time reducing the risk that you will attempt to identify it, a process sure to end in tears. Michael Kuo (of feels that advanced Russula identification “is a joke” with species distinctions frequently based on subtle, arbitrary and highly variable differences.1 It’s always good to be able to identify mushrooms to avoid eating toxic species, but with Russula, so far, this is quite a challenge. Luckily most Russula species aren’t harmful beyond a stomachache, however, one of a few toxic exceptions is the deadly Russula subnigricans.

image of Russula subnigricans from Imazeki et al.Russula subnigricans is a mushroom first found in Japan in 1955. Since then, it has also been found in China, Taiwan and has sometimes been reported in the Southeastern US.* It is one of the blushing Russulas, but it’s not shy: once broken, its tissues slowly bruise red. Two images of this species are shown here.6,4H They don’t look very similar to me— the cap colors and gills look very different (let’s go with the first one, which appeared in a book6 coauthored by the very mycologist who first described it). This demonstrates the variability of Russulas even within a species, or perhaps differences in opinion between experts due to the difficulty of identification. Scientists aren’t the only ones struggling with Russula identification; many people have misidentified this species and eaten it. One study reports that it caused a quarter of the 852 mushroom poisonings in the past 18 years in Southern China.4 Half the people who ate it died!

cycloprop-2-ene carboxylic acidThe horrible thing about R. subnigricans is that it causes rhabdomyolysis, or the breakdown of muscle tissue. This is a painful process that can lead to kidney failure. Rhabdomyolysis can also be induced by physical damage to muscle tissue, or abuse of drugs like cocaine. In R. subnigricans, the toxin that causes it is cycloprop-2-ene carboxylic acid— only recently discovered in 2009.3 Earlier studies found toxins dubbed russuphelins, but it was later questioned whether the researchers had identified their toxic mushroom correctly (darn you Russulas!).4 The reason it has taken so long to identify the real toxin is that it’s unstable, making its isolation and detection difficult; it is also not directly toxic to cells, further complicating experiments.3 Although the exact mechanism is not understood, the toxin appears to trigger a cascade of reactions in the body, resulting in widespread breakdown of muscle. If the muscles in your heart or your diaphragm get broken down, you’re in trouble as your heart may stop, or you may stop breathing. After muscle tissue is broken down, massive amounts of one of its chemical components (myoglobin) are carried to the kidneys. In high enough doses, this causes kidney failure. In terms of toxicity, 2.5 mg/kg of dried mushroom kills mice. If humans are like mice, then two or three mushrooms can kill a person.3

Russula subnigricans in Chen et al.Symptoms usually begin 30 min to 2 hours after ingestion and include nausea, vomiting, diarrhea and abdominal pain. These are common, non-specific symptoms of mushroom poisoning. However, within 6-12 hours victims also have general muscle pain, speech impairment, convulsions, pupil contraction, stiff shoulders, backaches, trouble breathing and myoglobinuria, which turns their urine red and contributes to kidney failure. Most deaths occur 12 to 24 hours after ingestion.4

Treatment for rhabdomyolysis in the case of mushroom poisoning is mainly supportive— there is no specific antidote. The victim is kept hydrated and dialysis may be performed in an attempt to prevent kidney failure. The main factors dictating survival are how much mushroom was consumed and how soon after ingestion treatment begins.

A few other mushrooms are known to cause rhabdomyolysis, including Tricholoma equestre (the Man on Horseback). It is globally widespread and was a treasured “edible” mushroom— at least until scientists discovered it caused rhabdomyolysis. A 2001 study examined the 12 cases of delayed rhabdomyolysis in France from 1992-2001. This study documented victims experiencing symptoms of rhabdomyolysis 24-72 hours after the last meal of T. equestre. Of the 12 patients, 3 died. To confirm T. equestre was the culprit, the authors experimented with mushroom extract on mice and determined it was indeed the cause.5 The specific compound causing rhabdomyolysis was not determined, but this mushroom is no longer invited to dinner. Now it reminds us to be humble, as there are many things we don’t know about this species yet, and furthermore about over 90% of fungi.

These deadly mushrooms serve as a reminder to respect mushrooms and correctly identify them before eating them. Mushrooms can do some pretty crazy complicated stuff and make some weird molecules we don’t understand. Even familiar mushrooms like T. equestre that we thought were safe sometimes turn out not to be. Although we now know the toxic component of R. subnigricans, we are still only beginning to understand its effects. With this in mind, if you find a Russula, you might as well throw it at a tree and enjoy the show

Of course, we do not really propose the wanton throwing of Russulas. Please let them live their lives. But if you’ve picked one by accident, by all means…

*Editor’s Note: The true identity of “Russula subnigricans” specimens found in the southeast US is up for debate–we have no reports of poisonings; they may well be a different fungus. It’s enlightening to consider this: the scientists who discovered the toxin3 had to go to great lengths to be sure they had the right mushroom to study. They compared two putative R. subnigricans collections: one from Western Japan and one from Northeastern Japan. They determined which was the true R. subnigricans by checking to see which collection was poisonous to mice.


  1. Kuo, M. (2009, March). The genus Russula. Retrieved from the MushroomExpert.Com Web site on October 26, 2013.
  2. Lee Po-Tsang, Wu Ming-Ling, Tsai Wei-Jen, Ger Jiin, Deng Jou-Fang, Chung Hsiao-Min. Rhabdomyolysis: An unusual feature With mushroom poisoning. American Journal of Kidney Diseases. 2001, 38(4); E17-U71.
  3. Matsuura M, Saikawa Y, Inui K, Nakae K, Igarashi M et al. Identification of the toxic trigger in mushroom poisoning. Nat Chem Biol. 2009, 5: 465-467. doi:10.1038/nchembio.179.
  4. Chen Zuohong, Zhang Ping, Zhang Zhiguang. Investigation and analysis of 102 mushroom poisoning cases in Southern China from 1994 to 2012. Fungal Diversity. 2013. doi: 10.1007/s13225-013-0260-7
  5. Bedry R, Baudrimont I, Deffieux G, Creppy EE, Pomies JP, Ragnaud JM, Dupon M, Neau D, Gabinski C, De Witte S, Chapalain JC, Godeau P, Beylot J. Wild-mushroom intoxication as a cause of rhabdomyolysis. The New England Journal of Medicine. 2001, 345(11), 798-802.
  6. Image of R. subnigricans from: Rokuya Imazeki, Yoshio Otani, and Tsuguo Hongo, (with photos by Masana Izawa and Nakahiko Mizuno). Fungi of Japan (Nihon no Kinoko). 1988. Yama-Kei Publishers, Japan. [ISBN-13: 9784635090209] One of the authors of this book, T. Hongo, was the first to give our fungus a name.7
  7. Tsuguo Hongo. Notes on Japanese larger Fungi (6). Journal of Japanese Botany 1955. 30(3) 73-79. [in which our mushroom was first named]
Kathie Hodge <![CDATA[Learning fungi]]> 2013-12-19T19:12:10Z 2013-12-19T19:12:10Z A reading recommendation from your editor, Kathie T. Hodge.

It’s hard to learn about fungi. And eww, why would you want to? Aren’t they all either diabolical molds or poisonous mushrooms? Of course not. Fungi are an amazingly old and diverse kingdom, yet hardly anyone knows much about them, even us mycologists. After all, we think that we’ve only even given names to about 5 to 10% of them. Not a typo.

So let’s say your interest is piqued— you want to know more. Good for you. You could go the mushroom route: join a club, attend forays, eat stuff, and learn from eclectic mushroom gurus. Yes, do that, it is fun, you will learn interesting things, and it will give you a window on some of the wonders of fungi. But most fungi –the vast majority of them– are not mushrooms. At some point you will start to wonder about all the rest.

Kingdom of Fungi by Jens H. PetersenHere is where most people get stuck. How do you begin to learn about the incredible variety of fungi? How they are related to one another; how they live? If you can even find one, you could take a college course: you’ll learn the secrets of fungi, capture them, and observe them up close and personal. Do that, excellent, but it’s not for everyone. You may hurt your brain or your wallet. If you are very brave, skip the class and get hold of a mycology textbook. You will fall asleep more quickly at night, because although the texts are good, they are dense, use lots of terminology, and are not so pleasingly illustrated. You might skip the textbooks and read some of the growing number of books that explore the stories of fungi, that is good too, yes! do that. Yet, if you are a visual learner, the emphasis on text over images may make you wish for more.

So do this: buy Jens Petersen’s book, The Kingdom of Fungi. Sadly, I haven’t met Dr. Petersen, but he is clearly very cool, and adventurously knowledgeable, and very adept with a camera. He’s created the missing piece, a joyful photo-essay on the glorious diversity of fungi. It will not hurt your brain or your wallet. Because of all the beautiful photos, you will hardly even notice you are learning things, that you are developing a structured view of the kingdom of fungi. As a teacher, I find that this structure gives us a comfortable place to put future learnings. That is, if you know a little about the kinds of fungi, you will have an easier time predicting the qualities of some fungus you’ve just encountered for the first time. His classification scheme is refreshingly modern; his pages are beautifully laid out. His photos of itty bitty fungi will (finally) convince you of the beauty and intricacy of smaller landscapes, and you may even find yourself wishing for a hand lens.

Amazon mystery tongue, by Jens H. PetersenFungi are cool, but they are foreign to us, and hard to get a grip on. So this question comes up a lot — how do I learn more about fungi? Here is a book for you and me. Not too much text, not much jargon. Enough order to help you build a scaffolding for your growing understanding. And lovely photographs to please anybody–over 800 of them in just 265 pages (have a look inside). There’s even an unknown fungus, the Amazonian mystery tongue, which is sticking its tongue out at us all, as fungi often do. I’m so happy to see this book, it makes for a great start in fungi.

Wishing you a happy journey and much joy in your fungal education.

Bonus! Bonus! Bonus!

Here is some juicy extra stuff for you.

  • For a limited time, you can listen to Jens Petersen (genius, see above), along with Lynne Boddy (fungus professor/genius) and Phil Ross (fungus artist/genius) via the BBC radio program, The Forum. I enjoyed this show, and note that Lynne and the host (UK) say fun-ghee. Jens and Phil (Denmark, US) try to say fun-ghee but seem to lapse into alternate pronunciations: fung-eye and sometimes fun-j-eye. In much of the US and Canada we say fun-j-eye with a soft J sound. Take your pick.
  • Interview with Jens H. Petersen by Pedro Crous. IMA Fungus, 4(1) June 2013, pp. 21-22(2). Open Access download.
  • Here is Dr. Jens H. Petersen’s website of fungal photographs. You can also find him via MycoKey, an innovative website that aims to help you identify fungi from around the world.

The image of the Amazonian mystery tongue is by Jens Petersen, and you will find its intriguing tale at the end of his book.

Kathie Hodge <![CDATA[How fungi grew on Cesalpino]]> 2013-11-01T15:12:38Z 2013-11-01T14:55:19Z

Andrea Cesalpino

Mold appears out of nowhere, doesn’t it? Baseball mitts left in the garage develop disturbing colors; perfect raspberries get furry in a wink. It wasn’t til 1729 that Micheli showed that fungi make spores that act like tiny seeds, which Bassi later found could cause disease in animals. Still later, Pasteur applied these ideas to humans, and thanks to him I did not die of rabies. But anyway, back in 1583 this chap here, Andrea Cesalpino, thought molds were more like crystals that sprang direct from the thing they grew on. So it struck me as funny when we found fungi growing on his own book.

That’s right, last year Cornell’s Library acquired an original 1583 copy of Cesalpino’s classic, De Plantis. It’s a seminal work, being an early influence on how we classify life today, and marking the revival of plant studies after the middle ages.3 Although remarkably clean for a 430 year-old book, it had some speckles and splotches. We looked at them under the microscope, and here is what we found.

430 yr old linen fibers and soot particlesWe found long twisting fibers of linen. Linen fibers refract the polarized light of my microscope into glorious rainbows, and the fibers are checked with little crossways lines. They are mostly made of cellulose, a strong and durable building material made by all plants. Among the linen fibers, we found angular black chunks of soot. Perhaps it is soot from the lamp of an ancient scholar who fell asleep while making the notes we found in the margins. The soot is not harming the book, just besmirching it.

We found mold. A Penicillium or an Aspergillus. We didn’t find much of it— most of the speckles and “dirt” in the book were soot. The few speckles of mold were small and who-knows-how old. We found two Alternaria spores. We found actinobacteria: they look like scaled-down fungi, but are a filamentous kind of bacteria. They are so small Cesalpino coudn’t have seen them and never imagined their existence. These molds and bacteria were not happy, because their book is not wet, and is unlikely to get wet again. Back in happier times, they found themselves on a damp spot, and set about eating the book. It is tempting to think of molds as a surface phenomenon, but molds grow in and along the cellulose fibers of the paper, digesting them. That’s why brushing molds off the surface of an old book doesn’t solve the problem. Drying can stop them, because nothing can grow without moisture.

Cesalpino would’ve said these molds and actinobacteria (if he could see them) were products of spontaneous generation. Poof! They just appear. For Cesalpino, green plants were fully alive and had seeds and also souls (which he speculated were seated in the pith, where the stem joins the root). He did not speculate about fungal souls, but you are welcome to do so in the comments. Here’s what he said about fungi:

Brown mold spores are much bigger than chains of Actinobacteria

Some plants have no seed; these are the most imperfect, and spring from decaying substances; and they therefore have to feed themselves and grow, and are unable to produce their like; they are a sort of intermediate existence between plants and inanimate nature.
A. Cesalpino in De Plantis (1583), quoted in J. Ramsbottom2 p. 14

There is nothing inanimate about molds, which have no problem spreading their spores around. When those spores land in the right place, they waste no time growing and making more spores. So wet books get moldy, it is a sad fact. Books are made mainly of cellulose, which is not unlike a delicious necklace of candy pearls. People can’t digest cellulose, because we can’t break the links of the necklace to release the pearls of sugar, but very many fungi can. In fact fungi are the most important cellulose degrading organisms on earth. Ancient paper-making techniques also incorporated animal-based glues. Modern paper might also contain resin, alum, and chalk.1 All but the alum and chalk can nourish the right fungus or bacterium.De Plantis, 1583, just a little bit moldy

Cornell Library’s Conservation department knows what to do with a moldy old book. Visit their blog to read about the initial diagnosis and Mary Schoenfelder’s loving conservation of this very book.


  1. A. Mosca Conte, O. Pulci, A. Knapik, J. Bagniuk, R. Del Sole, J. Lojewska, and M. Missori. 2012. Role of Cellulose Oxidation in the Yellowing of Ancient Paper. Physical Review Letters 108: 158301. DOI: 10.1103/PhysRevLett.108.158301
  2. John Ramsbottom. 1953. Mushrooms and Toadstools. Bloomsberry Books.
  3. Bremekamp. 1953. A Re-examination of Cesalpino’s Classification. Acta Bot. Neerl. 1:580–593.

Image Sources
Microscope images of soot and microbes by me, Kathie Hodge; photo of the book by Kent Loeffler, who recently retired— ack! My thanks to Michele Brown for sharing the privelege of working with such an old and wonderful book.

Kathie Hodge <![CDATA[The Cornell Hoot]]> 2013-10-17T17:03:52Z 2013-08-09T03:37:57Z By Kathie T. Hodge, your editor.

chanterelle thief approaching
When hunting mushrooms, it’s easy to lose students in the woods. That’s why we practice the Cornell Hoot. Learning the Hoot is a highlight of the first Fall field trip. With students gathered round, I describe the exquisite art of collecting mushrooms, hand out crisp Cornell apples and maps, and demonstrate the Cornell Hoot: a rising “Ah-OOOT!” My students shuffle uncomfortably, but soon they can’t help but smile. Now we practice together Ah-OOT! Ah-OOOOT! Ah-OOOOOT! Even the shy ones can’t resist it. We do it again in unison, very loudly. A distinctive sound.

In the field, we use the Hoot as others might use a whistle. Turned around? just issue the Cornell Hoot. The rule is: when you hear the Hoot… Hoot back. That is all. The Hoot enables us to find each other. At the end of the expedition, those who’ve made it back to the vans issue a great mustering Hoot guaranteed to scare your pants off, or make you laugh. It is extra-pleasing if a Cornell Botany class is skulking in the woods nearby–how they must envy our hooty camaraderie; our chutzpah!

I’ve wondered where the Cornell Hoot came from. I learned it from my predecessor, Dick Korf. Imagine my tingling excitement when I encountered this passage in the 1903 travel diary of my great-great predecessor at Cornell, George Atkinson, who was visiting the Botanical Gardens at Kew, in England:

“As time for closing the gates came on I heard musical voices from different parts of the garden sing “all out, all out.” A custom very old, and now it is such a perfunctory call that one can scarcely distinguish the words. It often sounds more like “Ah- —-laio”
George F. Atkinson’s diary of his 1903 tour of Europe

What if Kew’s ‘All Out’ was the source of our Cornell Hoot? Atkinson brought it home from Kew, and it’s persisted over a century? Passed like a game of broken telephone from one Cornell mycologist to the next? Tantalizing.

How does one reconstruct a sound that hasn’t been heard for many decades? I contacted Kew Gardens, where a bemused historian confirmed the call was practiced as late as 1916. What did it sound like? We don’t know.

I tussled mightily with this, enlisting help from reference librarians, botanists, and British mycologists. (Paul Cannon said, “UK mycologists don’t generally hoot, though they may exclaim “I say!” or similar phrases when encountering a particularly special find.” Considerably more genteel, I thought, than the exclamations of certain North American Mycologists). I browsed books about Kew, and this charming question haunted my dreams.

Then I heard back from Dick Korf. He said “Oh, it’s the Cornell hoot now, is it?” And he told me it was entirely his own invention. Recent and local, not at all what I was thinking! It made me laugh out loud. But an enchanting story still. Here’s his tale:

It was when I was at Ringwood with one of my first class field trips, maybe in 1951, and noticed that all students had not returned. I thought it to be the loudest and most distinctive calls in my vocal repertoire. I am pretty sure it didn’t come from one of the many plays I did as an undergraduate and graduate student, learning to project my voice, even a whisper, to reach the back row in the theatre, which Professor Alexander Magnus Drummond demanded of us.
Professor Emeritus Richard P. Korf

The Hoot is working at McLean BogsRingwood is a Cornell Preserve that is notoriously easy to get lost in. Once while I was picking up some Ringwood-bewitched students at the home of friendly neighbors, the neighbors told me the story of why it was called Ringwood. They said that in the early days, when the first growth forest there was being felled, the sound of axes rang in every direction, and even then lumberjacks lost their bearings there. There’s no useful topography to speak of, and sounds seem to come from nowhere, or everywhere. Despite all the hooting, I still lose students at Ringwood most years. Once I called state troopers to help with a search.

Sometimes lost students phone me on their cell phones, but since they are unable to tell me where they are, I can only reassure them, and give questionable advice on who to eat first. Unlike GPS devices and cell phones, the Cornell Hoot works quite reliably in deep woods and remote forests. It’s not as old as I thought it was, but nothing could make it less satisyfing to perform. I recommend it.


Disclaimer: Perhaps because I grew up in Canada, my Ah-OOT! verges on an “Ah-OUT!” Eh?
p.s. You can find Atkinson’s European travel diaries from 1903 and 1905 here.
Kathie Hodge <![CDATA[Azalea divinity]]> 2013-07-10T15:16:46Z 2013-07-09T17:36:30Z Thoughts on improbable fruits by Kathie Hodge. That’s me.

Only fools try to identify fungi over the phone. I once got a call about chaga (a sterile conk that is the life’s work of the fungus Inonotus obliquus), and I said “it’s pretty unmistakable…” only to later receive a photo of something quite other. And mushrooms implicated in poisonings are notoriously tricky to ID by phone, because one is prone to mislead oneself, and also to plant ideas in the caller’s head that turn out to be untrue. Bill Bakaitis wrote a thoughtul essay about this. But a while ago I got an email about shrubs sporting fruits of papier mache, and I dared to venture a guess.

The finder’s description:

…all the wild azaleas seemed to have white, chalky somewhat ball-shaped “growths” about 1 to 2 inches in diameter clinging near the ends of branches. It looked like someone had slopped some balls of papier mache on them, roughly. It most reminded me of divinity–the old-fashioned candy. This wasn’t around the flowers/seeds but was near them. Don’t know if it was a gall or a fungus or something else…

Late on a Friday afternoon I had the feeling so eloquently expressed by our cryptic Friday Afternoon Mycologist: a feeling of idle, end-of-the-week curiosity. So I drove right out there after work and had a look at those azaleas.

Exobasidium vaccinii on Azalea periclymenoidesThis Azalea–the Pinxter Bloom, Rhododendron periclymenoides– is uncommon around Ithaca but grows like a slosh of pink paint splashed southward down the eastern mountains of the US. Like other rhododendrons, it’s susceptible to a fabulous gall-forming fungus, Exobasidium vaccinii. No really, fabulous as in “if you’re growing rhodies, you’ll want this too.” The galls, also called Azalea apples, are said to be edible (but read on!). They’re mostly plant tissue, with a dash of fungus, and they’re big and juicy and a little sweet.

There are more than one hundred species of Exobasidium, all of them plant pathogens, and all finicky in which plant they’ll eat. Most modify some part of their hosts by altering the plant’s hormone levels. This gall is made of azalea cells that have been tricked into growing an “apple.” The white surface of the gall is busy with fungus, and the fungus, Exobasidium vaccinii, is busy making a ton of spores. Exobasidium basidia (b) erupt through plant cells to make basidiospores (sp) on the outside of a gall It makes banana-shaped basidiospores which in turn can sprout pointy little asexual spores. Either kind can blow or splash away to start infections in growing branch tips. They won’t blossom into full-blown galls til next Spring. Knowing their life cycle suggests a way to deal with them: snip off the incipient galls in springtime, before they produce spores.

Though I’ve heard of people eating these pinxter apples, azaleas and rhododendrons are poisonous plants. Their grayanotoxins mess up sodium channel functioning, and therefore your nervous system–nerves can’t turn on and off when they should. Most notoriously, grayanotoxins are concentrated in “mad honey” made by bees who visit Rhododendron flowers. Those who eat much mad honey become strangely intoxicated, dizzy, they conk out, and have slow and funky heartbeats for a day or more. Livestock may perish, but people seldom die from grayanotoxins. Well, unless you count that time when Pompey the Great’s soldiers were slain by their enemies while zonked on mad honey that had been sneakily left for them by allies of Mithradates VI. That was back in 67 B.C.: perhaps the first instance of biological warfare. Adrienne Mayor wrote a fascinating article about mad honey, and Stephen M. Henning presents some tales and lore about rhododendron poisoning. All this is to say, don’t eat Azaleas or Rhododendrons, or their galls.

Confessional: I said you’ll want these in your garden, but perhaps you don’t know me very well. Being a plant pathologist/mycologist, I look fondly on all sorts of blights, specks, spots, wilts, and galls. When I learned that horrifying masses of orange goo washing up on Alaska’s shores turned out to be fungus, I thought: Woo hoo! it’s about time a fungus that normally toils in obscurity got its 15 minutes of fame. So. We may not be of the same mind, you and I.

Further Reading

  • B.D. Compton. 1995. “Ghost’s ears” (Exobasidium sp. affin. vaccinii) and fool’s huckleberries (Menziesia ferruginea Smith): a unique report of mycophagy on the central and north coasts of British Columbia. J. Ethnobiol. 15(1): 89-98. [700kB PDF]. Read this, it’s great.
  • Bill Bakaitis. 2009. Diagnosis at a distance: Issues raised by a case involving GI distress and life threatening symptoms attributed to ‘edible’ mushrooms. [nothing to do with Exobasidium, rather thoughts on trying to ID some mushrooms in a poisoning case without specimens or photos]
  • Cornell Plant Disease Diagnostic Clinic. 2011. Azalea Gall.
  • Bill Cline. 2011. Exobasidium fruit and leaf spot. NC Blueberry Journal.
  • S.A. Jansen, I. Kleerekooper, Z.L. Hofman, I.F. Kappen, A. Stary-Weinzinger, M.A. van der Heyden. 2012. Grayanotoxin poisoning: ‘mad honey disease’ and beyond. Cardiovasc Toxicol. 2012 Sep;12(3):208-15. doi: 10.1007/s12012-012-9162-2. Free access via PubMed Central.
  • Adrienne Mayor. 1995. Mad Honey! Bees and the Baneful Rhododendron. Archaeology Magazine 48(6): 32-40. [a charming article about mad honey over the ages].

Images: Kathie T Hodge (Gall on Rhododendron pericylmenoides); E.A. Gäumann (from his clasic book Comparative Morphology of Fungi, 1928). Flickr photographer BlueRidgeKitties took a particularly nice photo of this disease. Wouldn’t the lovely pairing of azalea flowers and cheerful galls perk up your garden!

Thank you, Sandy P., for asking me about this in the first place.

Kathie Hodge <![CDATA[Mammoth Poo Fungi]]> 2013-06-02T16:44:16Z 2013-06-02T15:07:23Z Brett Cromwell wrote this post. This Spring he was a bright light in my class, Medical and Veterinary Mycology.

How many times have I caught my dog eating his own excrement? He always tries to lick me with that fresh brown smile. My dog’s not the only one doing it, either. Many animals chow down from time to time on their own poo: termites, rodents, rabbits… even woolly mammoths ate their own poo.

van Geel et al. provide this photo of ancient mammoth poop with spores insideHow do we know this? Mammoths have been extinct for thousands of years. We know because scientists found a fungus, Podospora conica, deep inside this dung ball (right).1,5 This poop looks almost fresh, but is about 14,000 years old and was found among remains of a woolly mammoth in northwestern Alaska. Podospora is a tiny, dark fungus that looks a lot like this. Since it only fruits on the surface of poo some time after it’s been pooped, the only way it could’ve gotten into the center of a mammoth nugget is if a mammoth had enjoyed a tasty number two snack.

Podospora belongs to a diverse group of fungi called coprophiles (a word that means “poo lovers” but sounds more scientific). You’ve already read about another famous coprophile, Pilobolus, here on the Mushroom Blog. Coprophiles live on poop, especially the poop of herbivores which contains lots of partly-digested, but still nutritious plant matter. Take a moment to imagine the difficulties of living on a piece of poop, and needing to get your offspring onto a new piece of poop. There’s more than one way to do it, but a popular choice among coprophiles is to shoot spores onto nearby vegetation,2 and hope they get eaten by a herbivore like a woolly mammoth. The spores then pass through the digestive system and find themselves in a fresh piece of poop, where they begin to grow. The fungus eats the poop for a while, then is confronted by the same problem: how do I get my offspring to new poop? So the fungus produces fruiting bodies on the surface of the poo, and off we go again. That’s what coprophiles do, and that is ALL they do—their whole world is crap.

Feeding on excrement is called coprophagy, and is not uncommon in the animal kingdom. Re-digesting feces can be a valuable way to get nutrients synthesized by an animal’s intestinal bacteria, like vitamins K, B12, and B7. The community of fungi that lives on poo might also release additional nutrients. Young elephants consume the feces of adults—apparently to obtain the bacteria they need for their own guts. Some animals practice coprophagy regularly; others do it out of desperation. Maybe it’s a harsh winter and food is scarce? Dogs are another question—I’m pretty sure they just do it to gross us out.

Woolly mammoths, from art by Mauricio_AntónSure, fungi can answer the burning question: did mammoths eat their own poo? But they might also shed light on mammoth extinction. Woolly mammoths were one member of the extinct genus Mammuthus and were found in Europe, Asia, and North America. In North America, mammoths died off around 12,900 years ago during the quaternary extinction event. Many other large mammals (our megafauna) died off then too. Why? Maybe it was climate change. Perhaps it was an impact from an extra-terrestrial object that led to sudden changes in climate.4 Scientists can’t quite agree about this. As a member of the human race I am more than happy to let the asteroid take the blame, but unfortunately another hypothesis is that ancient humans killed off the mammoths.

The first human settlers arrived on the North American scene 13,000ish years ago. Most came via a land bridge from Russia to Alaska, others perhaps by sea.6 Mammoths liked to eat poo; humans liked to eat mammoths, and they hunted them during the Pleistocene era and up until their extinction. Maybe they ate them all, or persecuted them enough that their populations crashed. So who gets the blame? Who would have thought a fungus might have the answer? A fungus that eats mammoth crap!

8 spores of Sporormiella australis, by Bjorn WergenScientists are using Sporormiella spores to study the prevalence and extinction of the woolly mammoth.3,4 Sporormiella species are coprophiles that, like Podospora, travel through a herbivore to complete their life cycles. In times when Sporormiella was very abundant (poopy landscape), a count of its spores in sediment cores can give an indication of just how poopy the landscape was.

Sporormiella spores are tough-walled and have a distinctive four-celled structure–each cell is marked by a “germ slit” like a papercut in the brown spore wall. There are many Sporormiella species and they aren’t specific to a particular herbivore’s dung. Each spore measures around 50 micrometers long–imagine trying to find these tiny specks in dark brown sediments. Researchers collected samples at various sediment depths in an Indiana lake, and counted the Sporormiella spores. Each sample depth correlates to a precise period of time. When the numbers came back the scientists were surprised: They found a decline in the number of Sporormiella spores starting almost 15,000 years ago, before any human interference or asteroid impact. Spore levels had declined to 2% of their former number by around 13,700 years ago.3 The decline suggests a population collapse but not a final extinction. This time frame roughly coincides with a period of warming before the asteroid collision. Perhaps humans weren’t fully to blame if mammoths were struggling before humans got there. It looks as if multiple factors are behind the extinction.

That a spore that measures five one-hundredths of a millimeter could be an reliable indicator of a six ton mammal that lived more than 13,000 years ago is pretty incredible. There’s some friendly debate about how far one can go with this approach, but there’s no question that fungi can be important clues to the past.7 I say, next time you pass by a pile of turd, show a little respect, it may be more important than you think.

Editor’s Note: Dr. Else Vellinga also wrote a nice article about dung fungi and what they can tell us. You can find her story (from Mycena News via MykoWeb) right here.

  1. van Geel, B., R.D. Guthrie, J.G. Altmann, P. Broekens, I.D. Bull, F.L. Gill, B. Jansen, A.M. Nieman, B. Gravendeel. 2011. Mycological evidence of coprophagy from the feces of an Alaskan Late Glacial mammoth, Quaternary Science Reviews, Volume 30(17–18): 2289–2303. doi:10.1016/j.quascirev.2010.03.008
  2. Deacon, J. W. (1997). Modern mycology. Oxford: Blackwell Science. p. 166. ISBN 0-632-03077-1
  3. Gill, J. L., Williams, J. W., Jackson, S. T., Lininger, K. B., & Robinson, G. S. 2009. Pleistocene megafaunal collapse, novel plant communities, and enhanced fire regimes in North America. Science, 326(5956): 1100-1103. doi:10.1126/science.1179504
  4. Mason, B. 2009. Dung fungus provides new evidence in mammoth extinction. Retrieved April 2013 from Wired Science.
  5. Reilly, M. 2010. Mammoths ate their own poo. Retrieved April 2013 from
  6. Maugh, T. H. 2012. Who was first? New info on North America’s Earliest Residents. Los Angeles Times, July 12 2012.
  7. A.G. Bakera, S.A. Bhagwatb, K.J. Willis. 2013. Do dung fungal spores make a good proxy for past distribution of large herbivores? Quaternary Science Reviews 62: 21–31. [this is a nice paper! --Ed.] doi:10.1016/j.quascirev.2012.11.018

Image Sources:

  • A piece of mammoth poop. Dung ball with Podospora inside recovered from mammoth remains near Cape Blossom, Alaska. Photo Credit and Copyright: Dr. Bas Van Geel (1).
  • Woolly mammoths, excerpted from a painting by Mauricio Anton. I think the third one is pooping, don’t you? Via Wikimedia Commons.
  • Eight spores of Sporormiella australis inside an ascus. Photo by Björn Wergen of a modern-day Sporormiella, used with kind and explicit permission.