Observation 191680: Amanita citrina f. lavendula group
When: 2014-10-03
No herbarium specimen
0 Sequences

-This specimen was associated with the soil, and more than one sample was collected. Each sample wasn’t growing next to each other, they were scattered around the area. Each sample that was collected was growing in solitary.
-There wasn’t a distinctive smell but wet dirt.
-The diameter of the pileus was about 4.0 cm.
-The surface of the pileus felt greasy and sticky to the touch. It was mostly smooth, but there were some “scales” that were assumed to be remnants from a universal veil.
-The pileal shape was broadly convex, and the margins were smooth.
-When the specimen was cut in half, the flesh was white in color.
-The white stipe was centrally located. It was measured to be about 7.2 cm in length and 0.61 cm in width.
-The stipe was also found to be hollow and somewhat clavate.
-The base was inserted/insititious.
-The surface of the stipe felt smooth and moist. It appeared to be fibrillose.
-The pileus and stipe didn’t display any noticeable changes when it was damaged with my pocket knife.
-The cream/white gills were free and even.
-It appeared to have two lamallae tiers that were arranged in a regular pattern.
-When the gills were damaged, there was some liquid that came out, but I wasn’t sure if it was water or latex.
-The base was bulbous. I wasn’t sure what type of volva it was. It was assumed to be a napiform type.
-The spore print was white. Under 40x magnification, the spores appeared to be clear, smooth, and round.
-When the whole structure was cut in half, part of the flesh, inner stem, and volva was filled with some soft gelatin material.


Stick surface revealing some discolor from the universal veil
White gills and annulus
Soft gelatin-like material inside the structure
Mb63 spore.jpg
Smooth, round spores under 40x magnification

Proposed Names

81% (1)
Eye3 Eyes3
Recognized by sight: White, bulbous looking base, annulus
Used references: Mushrooms of the Midwest by Michael Kuo and Andrew S. Methven
Based on microscopic features: Smooth round spores

Please login to propose your own names and vote on existing names.

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Thanks for your response.
By: R. E. Tulloss (ret)
2014-12-04 17:38:36 PST (-0800)

I wouldn’t worry about measurements at 40X.

You really can hardly tell whether you are looking at the side of spore or the top or bottom or one end or the other. Everything looks very round.

By the way, no one can really see hundredths of a micron even at 1000x, you should round to tenths at high magnification. From the numbers you gave, I would take the values 7.8 and 7.6 or 8 and 8 given the low magnification. Essentially, you report a spore with a length/width ratio of 1.0…a globose spore. Since even the roundest spores have a flattened area next to the apiculus, you really won’t find many spores with length/width = 1.0 when you measure at highest magnification.

In fact, in order to have a standard way of measuring many mycologists always follow the rule of measuring a spore only when it is in lateral view. This is when the apiculus and both end of the spore are in focus simultaneously and the flattened area next to the apiculus is visible. With the roundest spores this goal is hard to achieve, but worth trying on the chance that two species will have subtly different size/shape once you have measured a large sample of spores.

My suggestion is don’t begin mycology with a project that requires measurement of a lot of globose or subglobose spores. Give yourself a break! :)

I’m working on the lavendula group of sect. Validae and on lots of taxa in sect. Vaginatae. Lots of very round spores. Lots of microscope hours. You’d think I’d develop more patience after all the time I’ve spent at this. However, after 90 minutes or so, I’m really hoping for the twentieth spore to pop up and be counted/measured. Always worth doing, however.

Very best,


Thank you for your insight , Rod
By: Marielle Biscocho (mbiscoch)
2014-12-04 14:33:30 PST (-0800)

I am a beginner mycologist taking a fungi class. Unfortunately, due to the limited amount of equipment available to me, I wasn’t able to measure the spores for this specimen at a higher magnification. I was only able to measure at 40x magnification—anything higher, the image would become too blurry to make measurements.

If the microscope was calibrated correctly, my spore measurements are as follows:
7.76 (L) x 7.56 (W) micrometers.

It’s nice to see people taking notes on the fresh material.
By: R. E. Tulloss (ret)
2014-12-04 14:15:50 PST (-0800)

The gelatinous appearance in the interior is caused by the normal tissues becoming watersoaked. This also relates to the liquid (water) coming from the gills when they were cut. Since the material is from North America, it is not likely to be A. bulbosa (correct name for the European A. citrina).

It’s most likely to be one of the three taxa of the “lavendula” group. We have been trying to separate these taxa with something in addition to gene sequences. If you are able to measure the spores at a higher magnification (closer to 1000X), you might get lucky and identify the one species that has distinctive spore size/shape.

I know that I’ve written a comment like this recently, but I can’t remember to whom I wrote it. Please forgive me if this is a repeat.

The present data about the three taxa are here:


Very best,


Created: 2014-12-04 13:34:51 PST (-0800)
Last modified: 2014-12-12 21:51:21 PST (-0800)
Viewed: 41 times, last viewed: 2017-10-15 02:52:19 PDT (-0700)
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