Jump to content

P. pulmonarius or pleurocybella?


MicroDoc

Recommended Posts

I'm almost sure that i (finally) found pulmonarius but certain aspects are bothering me.  In favor of oyster- short stalks with decurrent gills and the smell is faintly fishy.  In favor of angel wings- pure pure white (they have turned slightly off white in the cooler...) and thin edges that fray ~easily.

I know that one of the best indications is hardwood vs. conifer.  The area is primarily hardwood but with eastern hemlock interspersed. I could not determine the wood.

So, what do you think?

IMG_20201025_095800.jpg

IMG_20201024_133522.jpg

IMG_20201024_133653.jpg

IMG_20201025_095830.jpg

Link to comment
Share on other sites

Wood does not look like hemlock or pine, and the surrounding forest appears to be composed of hardwoods. Pleurocybella porrigens grows on conifer wood, usually hemlock in my experience. Also, the well-developed stalks suggest Pleurotus pulmonarius, which does produce white fruit bodies.

This question is easily settled with a microscope capable of 400x magnification. Pleurotus mushrooms have ellipsoid to cylindric (fairly elongate) spores; Pleurocybella porrigens has spores that are only slightly different than round (subglobose to broadly ellipsoid). 

Link to comment
Share on other sites

I'm an amateur mycologist.

I use two microscopes. One is an old beat-up used monocular scope I got for $50. It has an eyepiece micrometer installed. I use this one to photograph spores at 400x. I load a photo onto my laptop, enlarge the photo, and then use a small piece of paper folded into an irregular pentagon to estimate spore dimensions. For a microbiologist this method would likely be unacceptable. But, over the years after many times having estimated spore measurements for material of which I was quite confident of the ID, I have found my estimates to be acceptably accurate. I do not estimate like this beyond 0.5 micron accuracy. 

My other scope is a binocular scope I purchased from AmScope for $200. I can see much better detail at 400x --ie spore ornamentation-- using this scope. But photos taken through one eyepiece of this binocular scope are not useful. I use this scope to assess more subtle traits like spore ornamentation. 

The more difficult issue is obtaining Meltzer's reagent. It is often necessary to mount spores/tissue in Meltzer's in order to assess the more subtle microscopic traits. 

A microbiologist would have access to a laboratory equipped with much better equipment than I use. A microbiologist would employ techniques much more refined than mine. But, my $250 approach to examining microscopic fungal features has allowed me to considerably expand my horizon of understanding. 

The main point here is that learning identification of fungi potentially places one onto any of a series of plateaus. Gross morphology can only get one up to a level where many questions cannot be satisfactorily answered. Beyond the level at which I comfortably function, there are much more refined means by which one may analyze fungi. Occasionally, I have the opportunity to submit a specimen to someone who possesses the means to subject material to more rigorous analysis, for example DNA extraction/analysis. To this end, I routinely dehydrate, label, and store material for potential study. 

If one wishes to make a distinction such as Pleurotus pulmonarius vs. Pleurocybella porrigens with ultimate confidence, then one needs more than just appearance and habitat. In this particular case, assessing differences in spore morphology for a sample of 20-40 spores well-focused at 400x would be telling. 

Link to comment
Share on other sites

The more I learn, the more I realize how many things I don't know.

This is particularly true of classification of fungal species. After about 20 years of hunting mushrooms and relying upon my collection of field guides I had gained a reasonable understanding of the local edible types and their look-alike species. Out of curiosity I started bringing home other types just to see if I could put names onto them. Then, the sea change... a digital camera and the Internet. When I first started using Mushroom Observer in 2008, most of my ID proposals were made at the highest level of confidence. But, after 12 years of learning about the complexities involved with species identification, many of my proposals are now made at lower confidence, despite my having become a better identifier over the past 12 years. To a great extent, my initially inflated confidence back then was a result of having basically studied in isolation (with the exception of one local friend who still maintains a casual interest in mushroom ID). One thing that eventually became apparent to me was that I had acquired a few misconceptions; for example attaching incorrect names to entities that I had come to recognize in the field. Then, there was the whole DNA thing that revolutionized the science of fungal taxonomy. Many new names and in some cases what seemed like contradictions... wide morphological variation within a single species concept, or conversely examples of seemingly identical specimens that represent separate taxa. 

So, is it possible to distinguish Pleurotus pulmonarius from Pleurocybella porrigens? In the field, one may presumably rely upon a combination of gross morphology and substrate. Presence of a well-developed stipe means Pleurotus; no stipe, Pleurocybella. Hardwood correlates with Pleurotus; conifer with Pleurocybella. But, there are reports of Pleurotus inhabiting conifer wood. Does Pleurocybella ever inhabit hardwood? I believe the current consensus is "no". Could this consensus possibly change at some point in the future? Yes. Does Pleurocybella sometimes develop a stipe-like base on a fruit body?  What if the type of wood is not known, or if the type of wood is misjudged? Well, then spore morphology comes into play. Is there a chance that at some point in the future what we believe we can tell from the spores will change? For now, I'm going with "no", but this may just be wishful thinking.

Here's an old MO observation of mine for which I just now reduced my initial confidence in the ID. I should have scoped the spores! Still learning.     https://mushroomobserver.org/180254?q=1W1oL   

Link to comment
Share on other sites

Great stuff.  As you write above, the morphological variations within a single species can be very confusing- old or young? type of wood? sun exposed or not? substrate differences...  just so many factors.  I was nodding my head reading that you have less confidence in id because of more experience.  That's biology- the more you know, the more that you understand what you don't know and the more aware you become of the complexity and the exceptions.   I'm always telling my students that biology is messy and almost anything I tell them will have exceptions.  I'm always telling my Biology I students that we are only scratching the surface with every topic we cover. The students who enjoy the complexity and "messiness" of biology, stick with it.  The others migrate to other fields.

At this point, I only trust the experienced folks on this website especially when it comes to id, especially if I'm thinking of ingesting something.  But I'll often go into Google images and plug in a genus and species-- I have to conclude that there exists a significant amount of erroneous information.  I've just started acquiring mycology books and I plan to join the NJ club and go on some "forays" with more experienced folks.

Anyway, the microscope. I've been offered "retired" microscopes and binocular scopes several times over the years.  I always refuse because I'm at the lab several times each week.  Why would I need a scope at home?  At the present time, I have to get permission from the Dean to even get on campus.  Strange times.  Next time I'm offered a scope, I'm going to take it.  I also have (in non-covid times) access to everything I need to extract DNA from any type of cell but I don't have a budget to buy materials needed for genotyping or sequencing.  I'm thinking about that. Small grants are not difficult to get and there is a budget for students doing honors work.  I'm thinking about playing with Entoloma abortivitum...

 

Link to comment
Share on other sites

E. abortivum would be an interesting thing to sequence... either the Entoloma mushrooms or the aborted Armillaria fruit bodies. 

A couple years ago I got my local club funded for 30 sequences through North American Mycoflora Project. This project now goes under the name Fungal Diversity Project  https://fundis.org/  . Here's my contributions from 2018.  https://mushroomobserver.org/project/show_project/240?q=1W4GY     https://mushroomobserver.org/project/show_project/241?q=1W4GY  . Click on "show" where it says "observations". I plan to apply for another grant --maybe next year-- if it's still available. I've been a bit too busy these past two years to devote proper attention. 

Link to comment
Share on other sites

Thank you Dave!.  As a certain comic might say-- "Very nice".  Thanks for the links. I'm getting excited about this. It seems like it could work out well for student honor's projects (that is once we are all vaccinated...).  I'm seeing several active projects close to me.  In fact, the closest appears to be a community college club.  

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Terms of Use | Privacy Policy | Guidelines | We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.