Mushroom ID Part II
Identifying an unknown mushroom is a methodical process. The basic process is:
I will describe the identification process that I personally use. My method typically involves documenting key features in the field, but digging into the books after the foray is over. This method requires that you take good notes, and good photos! You will want the following materials:
Documenting key features
As you could guess, you won't be able to arrive at a proper ID without checking out all the key features of the mushroom in question. What you want to generate is a list of features that you can compare to the feature list of potential candidates in your field guide. These features will be essential in the "keying out" process, which is based on feature combinations.
The Identification Pt. 1 section of this website is dedicated to major key features. Each category in the Identification Pt. 1 section was specifically chosen based on the major features that are noted in field guides. Become familiar with these, and note them as you see them.
Almost every feature should be visible in the field. The only one requiring additional effort is the spore color. Sometimes, you will be fortunate and find a spore deposit on materials beneath the mushroom cap. But when you don't, you'll need to collect a sporeprint.
I prefer to keep a small notepad with me, and for each specimen, document all the key features I can on a single page. I'll label the page with a number, which will correspond with photos and a sporeprint.
For me, photography is critical to my identification process. In the field, you are often surrounded with distraction and constriction: mosquitos, poor weather (or the promise of), limited time, and the allure of ever more interesting mushrooms to find. It is a great relief to know that your field work is separate from your academic work; you can save the book delving for the campsite / office.
When you are taking photos to support the identification process, your approach will be different from purely aesthetic photography. The basics still apply, of course, such as proper focus and lighting. But the ultimate goal is to capture as many key features as possible in the photograph. You are photographing the specimen in lieu of gathering it. This gives you the advantage of always having access to the mushroom in its fully hydrated, undamaged state. Would you expect a picked specimen to remain pristine in your basket after a day's worth of hiking the woods? This is not to say that you shouldn't hold on to your specimens. If you think your find is interesting and uncommon, you could dry it out and submit it to the Arizona Mycota Project.
Here is a list of tips for getting the most out of your field ID photos:
Be sure to check out these great mushroom photography tips:
Keying out unknowns
Most field guides have a step by step process of narrowing down the identity of your mushroom based on its key features. This branching selection process is called a dichotomous key, as you make yes/no choices to arrive at a possible match. Using this identification method is referred to as "keying out".
Here is a good example of a dichotomous key, as taken from mushroomexpert.com:
Key to Gilled Mushrooms
Kuo, M. (2007, March). The gilled mushrooms ("Agaricales").
In the above example, there are additional keys in the Gilled, Dark / Pale Spored categories that continue the process.
It will be useful for you to keep track of your route through the key. If you come across a decision that could go either way, write that down and come back to it if you arrive at an ID that you disagree with. Try different routes on the close call decisions, and you may find an ID that you can agree with.
Making your final determination
Once you arrive at a possible ID for your unknown, you will need to confirm wether this entry correctly describes your unknown. You need to scrutinize every key feature listed in the description, and compare it to your notes. It is not uncommon to find minor inconsistencies, but anything significant should make you reconsider your identities.