Species Feature #9, Ash-Tree Bolete

This feature is long overdue. In many ways the ash-tree bolete (Gyrodon merulioides) should have been Species Feature #1. Without this mushroom, my blog wouldn't exist. It was my first mycology success story: I encountered several specimens growing just outside my apartment. I had no idea what they were, but was able to get a tentative ID from one source. Since I was inexperienced, I really wanted corroboration - so I Googled the scientific name. At the time, one of the first search results took me to a post in this livejournal. It's written by a zoo employee in New England, and it planted the seed that grew into my idea for this blog. My introduction to this DC area blog by Laurel was, I suppose, the fertilizer. But it was my interest in G. merulioides that served as the soil. My blog's synthesis bears remarkable parallels to the ecological niche occupied by this species.

One largish specimen

Gyrodon merulioides Quick Facts

Common Name(s): ash-tree bolete

Taxonomic Breakdown:

• Kingdom - Fungi
• Subkingdom - Dikarya
• Phylum - Basidiomycota
• Subphylum - Agaricomycotina
• Class - Agaricomycetes
• Order - Boletales
• Family -Paxillaceae
• Genus - Gyrodon
• Species - merulioides

Range: I couldn't find information directly on the range of this species, but it is limited to the range of ash trees. Most commonly it is found under white ash, Fraxinus americana.

Just a small sampling of the hundreds of specimens I found one day in Silver Spring

Because of its proximity to white ash, the ash-tree bolete was long thought to be mycorrhizal.This is generally the case when a mushroom species is found exclusively under one species (or in this case, one related group of species) of tree. Yet the life of G. merulioides is more complex than that. It instead participates in a totally different symbiotic relationship - with a species of aphid which itself only feeds on ash trees. Meliarhizophagus fraxinifolii, according to this press release, fights predation by breeding wildly... so wildly, in fact, that some generations are born pregnant. I won't pretend to understand how this happens, but it adds one more layer of fascination to the scene.

Unfortunately, in the 1990s a fourth species entered the picture: the emerald ash borer (Agrilus planipennis), often referred to as simply EAB. This species of beetle decimates populations of ash trees, and threatens the entire genus. I have previously written about invasive species, taking the position that we are often too quick to label introduced species as damaging to their new environments. However, this seems like a clear-cut and very serious problem. Forests in this area can ill afford the loss of yet more tree species, and the EAB threatens several, and no North American species of ash tree has yet shown effective resistance to infestation. Lose the trees, and this biome loses the aphid and the mushroom mentioned above. Lose the aphid, and its predators lose a food source which rapidly replenishes itself.

Collecting spores.

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This mushroom is easy to identify if one knows what to look for. From above, the irregular, leathery, brown caps can be easy to miss, but once seen these alone are a good indicator of what you're looking at. The stem is lateral and often not very substantial. Underneath, the pore surface is a solid yellow with hexagonal pores. The light yellow (sometimes white) flesh of this bolete, like that of many boletes, bruises blue. A spore print usually isn't necessary for identification, but if taken it will appear olive brown. If you're unsure, look around for ash trees.

Note the blue bruising, and how the pores peel away from the flesh as a discreet layer.

June Mushrooms

June is already drawing to a close, but most of this month has been so dry here that I haven't really seen a lot of mushrooms. Honestly, this whole year has been pretty weak for my mycological exploits - but enough whining. June is when mushroom variety really begins to assert itself. As always, let me warn you not to eat any wild mushroom (even those I say are safe to eat) unless you know what you're doing. There is too much room for error between my blog and your plate to use this as an edible mushroom guide.

With the exception of morels, most of the mushrooms seen in May can still be found in June (nature, of course, isn't as conveniently divided into months as our calendar). The coprinoid mushrooms (inkys) are a bit more scarce by this time, but I did see a batch of them just yesterday afternoon while walking the dog. The ubiquitous oyster mushroom can also still be found. If you were to walk outside on June 15th and wander long enough, you could probably encounter most mushrooms from last month's post in addition to those featured below.

A personal favorite of mine, the ash-tree bolete (Gyrodon merulioides), begins to fruit in June in this area. For Silver Spring residents, these grow gregariously and predictably in Falkland Chase Apartments (where I used to live) from mid-June through late July. You can find them to the North of East-West Highway in the courtyard which lies just behind the big sign (weather conditions permitting, of course). I find this mushroom absolutely fascinating, as it can only be found near white ash, though its relationship to the tree is indirect. It exists only in the presence of a species of aphid which in turn only eats white ash leaves. Unfortunately, its taste is, erm, not good. I'm being charitable.

It's ugly and it's gross, but it's interesting.

In the showy category is the pretty - and often huge - Chlorophyllum molybdites. I have found a number of patches of these in the greener areas around downtown Silver Spring. They are easy to identify because they resemble parasol mushrooms but have green spores. The spore print they make is, in my opinion, about as beautiful as this hobby gets. As they age, specimens of this mushroom will literally become green around the gills. They'll make you sick, though, so don't eat them.

A button sitting on the gills of a mature specimen. I believe I measured this one at an eight inch diameter.

An unusual but commonly found summer mushroom is the crown-tipped coral (I know it as Clavicorona pyxidata, but it has many synonyms). This is another easy-to-identify mushroom because unlike other similar species it grows from rotting wood.  If it looks like the photo below and grows from wood (not terrestrially), then you can be pretty sure you're looking at crown-tipped coral. Then, it can be eaten! But not too much, because it is known to have a laxative effect. I have tasted this, both on its own and in an omelette, and would rate it as "passable."

One of the first wild mushrooms I tasted, this specimen was found in Shenandoah National Park.

The tree ear, or jelly ear (Auricularia aricula), is another interesting mushroom that I usually start seeing in June. It's a jellylike but still somehow leathery mushroom which grows from trees and logs. It's fairly distinctive and can be seen just about anywhere in this area if one looks hard enough. The odd thing about this one is that mycologists have been known to chew it like gum while out on a hunt. Now, I love mushrooms, but... well, YUCK.

When I see this, I don't think "chewing gum," but to each his own I suppose.

Unfortunately, in June I have also encountered Amanita phallioides and Amanita virosa (known as the "death cap" and the "destroying angel," respectively). I could get technical about things like "species complexes, but I feel that such digression would cloud the issue that THESE WILL KILL YOU if eaten. The Amanita genus in general should be avoided and its characteristics learned by those who have any intent at all of eating wild mushrooms. These two mushrooms are the greatest contributors to the death toll of the unwary.

This scratches the surface of what a mycologist can find this month. After all, I've covered only six species plus another handful of May leftovers. I wanted to highlight the variety of mushrooms out there by showing a few vastly different ones rather than inundating my faithful readership with page after page of photos and descriptions.

Edible Mushrooms in the Capital Area, Part 1

There is a technicality I must get through before posting about eating mushrooms. I have to warn you that unless you know what you are doing - and I mean REALLY know, not "I read about this mushroom in some guy's blog" know - eating wild mushrooms is incredibly dangerous. In this part of the world, there are approximately a half-dozen very common deadly poisonous mushroom species. There are quite a few more which are much less common. Others will not kill a human being, but will make most of us very, very sick. There is at least one species which is perfectly edible but will cause violent nausea and vomiting if alcohol is consumed up to three days before or after eating. Sometimes the substrate (what the mushroom is "eating") can add poisonous qualities to an otherwise safe find; man-made effects can cause similar problems. Even edible mushrooms can provoke allergic reactions in some people, and since most people have not been exposed to a wide variety of wild mushrooms these reactions are largely unpredictable.

It is not the existence of these poisonous species that make mycophagy dangerous. After all, there are deadly poisonous plants, fishes, and so on, and no one tells us not to take up fishing or eat wild blackberries. What makes wild mushrooms so dangerous is that species are not readily identifiable by sight in most cases. A significant amount of work is necessary to determine precisely what mushroom you have, and it is often a very subtle characteristic that separates the deadly from the delicious. Sometimes proper identification requires a spore print. Often a mushroom's environment removes characteristics that have a bearing on identity, such as a ring on the stem (or stipe, if you want to be pompous about it). Sometimes there is more intraspecies than interspecies variation in physical traits.  Further muddying the picture is a simple lack of background science - countless mushroom species are as yet unstudied. Even some of those which have been known and collected for centuries are subjects of taxonomic arguments.

I hope the above has made my point. I fully support new initiates into the hobby of mycology...but if you find yourself intrigued, don't use my blog (or anyone else's) as your point of reference. Understand that it is a hobby to be taken seriously. It can, however, be very safe if the proper cautions are exercised. This means 1) learning to identify all deadly poisonous mushrooms in your area, 2) never eating any mushroom you have not identified with absolute certainty, 3) progressing slowly with small samples for first-time tasters, and 4) never ignoring one trait because another gets your hopes up. With that in mind, I recommend Musroom Expert as an online resource. This book was my first on the topic, and it is written with whimsy alongside real knowledge. Supplementing a fun book like this with a more complete guide, like Audubon's or Simon and Schuster's, is a good place to start.

Now that I have frightened you, and subsequently bored you, I present the photographs. All mushrooms pictured below are specimens found in the Mid-Atlantic United States, and all are edible. In fact, all of these were found within two hours' driving distance from Washington, DC.

Clavicorona pyxidata - one of the first I ate, as it was an easy ID. The closest thing this species has to a common name is "crown-tipped coral." Similar but inedible species grow from the ground and not on wood.

Gyrodon merulioides - This ugly and foul-tasting (but technically edible) mushroom is sometimes known as the ash-tree bolete. It grows like crazy in my apartment complex from late summer through the fall. Its redeeming quality is its fascinating ecological niche. It is only found near ash trees - not because of the trees themselves, but because they are symbiotic with a species of insect which feeds only on ash trees.

In the foreground is a specimen of Cantharellus cinnabarinus (cinnabar-red chanterelle). The background is a mixture of these and Cantharellus lateritius (smooth chanterelle). They were part of a wonderful meal.

Auricularia auricula...known variously as tree ear, jelly ear, and (thanks to racist biologists of bygone days) Jew's ear. Apparently some mycologists treat this like chewing gum (yuck).

Orange jelly, aka Dacrymyces palmatus, is edible...but I haven't been quite so adventurous yet, myself. When a close relative is called "witch's butter," I am somewhat put off.

This is another I've not yet felt bold enough to try, Hericium erinaceus. Colloquially known as the "bearded tooth" this mushroom is odd in oh-so-many ways, not least of which is that one can eat something that looks and feels like this.

Hungry yet? My mouth is watering at the prospect of a new mushroom season. Morels should be appearing right about now in this part of the country. Alas, I've yet to encounter any of these lusted-after but elusive gems in my young mushrooming career. When I do first find this crown jewel of fungi, I'll be sure to share photos and accounts of the dining experience here.