Observation 182418: Amanita sect. Vaginatae sensu Zhu L. Yang
When: 2014-10-10
Who: zaca
No herbarium specimen

Notes: These specimens are very similar to others considered in previous observations (see e.g. observation 95540 and observation 84433), though found at a different place.
Growing on a mixed forest, mainly of pines and oaks.

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Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

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Yes, again, with regard to colors.
By: R. E. Tulloss (ret)
2014-10-12 16:56:15 PDT (-0700)

That’s why it is very useful to use a color book with a coding system.

In Kornerup and Wanscher, the color “hazel” is 6E8.

Munsell is a professional color encoding and color making company. They use a well-developed and widely adopted system. Again the problem is getting access to the right sets of colors for the fungi in which you are interested.

Bas told me to get the Munsell Soil Color book. It has a tremendous number of shades of browns. Not every amanita cap color is in the book; however, you can get close. On the upper left of WAO taxon pages, one of the teaching bits is related to color codes. You can see some ideas for color coding their. Used book stores might be a place to look; however, you will still find the books are rather expensive because many are out of print.

Very best,

Rod

Simply: “takes all kinds to make a world.”
By: zaca
2014-10-12 16:10:14 PDT (-0700)

Thanks you so much for these instructions, remarks and all that useful material.
Only two small remarks:
1- Colours are very difficult to describe; very often two persons refer to colours they saw in completely different terms, especially if there are mixtures and tonalities.
2- I have to adapt your “modus operandi” concernig measurements of spores, because I’m not able to measure them directly from the microscope, only from the photos taken. This means that I have to fix a way to take the pictures for future measurements.
Kind regards,
zaca

Now you see why my average Q is often a little higher (in some cases much higher)…
By: R. E. Tulloss (ret)
2014-10-12 15:44:35 PDT (-0700)

than that reported by other people.

I happen to find spore measurement a relaxing thing to do. I guess it “takes all kinds to make a world.”

:)

Rod

You’re absolutelyl right about color.
By: R. E. Tulloss (ret)
2014-10-12 15:42:52 PDT (-0700)

There has to be some standard. A long running standard is the book I cited, by Kornerup and Wancher. Ridgway’s guide was hand colored. It is indeed a wonder, but most specimens of the book have been heavily used over the last 100 years or so. The color wears off sometimes. And the colors were not perfectly identical from book to book. I still use the best copy that I have been able to find; however, it is just too expensive for someone just starting out. For that matter, Kornerup and Wancher is not cheap (under $100 the last time I saw a price on one, but not much under $100). I think in this case, the image in mind is the outside surface of a hazelnut (but the K&W image is a little darker than that). In your images the caps are much lighter and lack the orange component.

My method of measuring spores is very strict. It can take me hours to find 20 spores in the case of a specimen with subglobose to globose spores; however, if I don’t use this method, I will turn up with with lots of Q values = 1.0, which is true of a lot of spores rotated out of position for measurement in the Vaginatae. The number of spores with Q = 1.0 should not be very high at all. This is because all Amanita spores have (on one surface) a slightly or strongly flattened region called the “adaxial flattening.” It is immediately adjacent to the apiculus. Since I want to measure spores only when they are in a position that can be easily recognized (by me and by people wanting to replicate my results or counter them), I don’t measure a spore unless it is in lateral view. Lateral view is defined by the following, both ends of the spore are in focus and the apiculus is in focus. When this is the case, you have a side view of the spore and can see the adaxial flattening. When the spore is in this position, you will only have a Q value of 1.0 in the most nearly globose spores that you will every find (which are not too numerous).

OK. So that’s item number one, a spore can’t be measured unless it’s in lateral view.

Now you need a randomizing element so that you don’t accidentally follow some inate tendency to always measure the largest spore (for example). The randomizing process also must be followed very strictly. Start with your objective in one corner of your slide. Let’s say that, from the corner you choose (you can adjust the rule for any corner) the most distant corner requires the apparent [i.e., as seen through the eyepiece(s)] movement of the microscope stage up and to the left. Then follow this rule, move up until you find a spore that is in lateral view then measure that spore. If you can no longer move up, move left about the distance corresponding to the diameter of the region you can see through the eyepiece(s). Then move down until you see a spore in lateral view to measure. When you can longer move down to find a new spores, move left one visible area diameter (as before) and move up until you find a spore in lateral view that can be measured. Continue until you’ve measured 20 spores or you run out of space.

If you see very small or very large spores that are in lateral view but are not to be measured per your randomization rule, go ahead and measure them if they are candidates for the lower or upper extreme of your measurements; however, do not count them among the 20 spores, do not use length, width or Q data from these “extremes” in computing any averages. They are simply for use in indicating the largest and smallest spores you saw.

Finally, at least if you are not looking at amyloid spores in Melzer’s Reagent (when you may not be able to see spore contents), do not measure a contentless spore. It isn’t mature enough to have had its genetic contents injectes into it.

This is the shortest version I’ve ever written of this information. I worry that I have left out some subtlety. However, I think this will work well for you although it will require patience in the execution.

Very best,

Rod

Thanks, Dr. Tulloss, for the comments.
By: zaca
2014-10-12 14:35:29 PDT (-0700)

As a matter of fact, this time, my proposal of Amanita dryophila was based on the description given at
http://www.amanitaceae.org?Amanita%20dryophila.
You have to understand that for layman, like me, it is very difficult to know what is the meaning of “hazelnut brown” when applied to the description of an Amanita sp.. Are the colours of my specimens farway from that colour?
Another point is the measurements of spores: Given the amount of material in the photographs we have (say) hundred of spores potential candidates for measurements. How to choose? In the present case, I found the obtained values “similar” to those given in the description, which in addition to the macro characters make a “good picture” for a candidate of that species, the best I was able to find.
Thanks again and kind regards,
zaca

The original description of dryophila says the cap is hazelnut brown.
By: R. E. Tulloss (ret)
2014-10-12 14:04:11 PDT (-0700)

Using the Methuen Handbook of Colour, I find that “hazel” is a deep orange-brown with a bit more orange than a dark umbrinous brown. I don’t think the cap color is a very good match for the protolog. Sadly, the protolog does not tell the ratio of the length of the cap’s marginal striations to the radius of the cap. In sect. Vaginatae this is very important.

Here

http://www.amanitaceae.org?Amanita%20dryophila

I report spore measurements made on a specimen that was one of those cited in the original description (i.e., a paratype) as well as on another specimen (not cited in the original description) sent to me by one of the authors of the species. According to spores measurements based on those collections, the spores in the present material (broadly ellipsoid on average with about 95% having Q less than or equal to 1.2) are more nearly globose than those of the material of dryophila that I have revised.

It is important to say that I have not seen the type of dryophila.

This is an interesting collection.

Very best,

Rod

Created: 2014-10-12 09:56:27 PDT (-0700)
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