Collection location: Plymouth Twp., Luzerne Co., Pennsylvania, USA [Click for map]
On grass ~ 25’ from Oak, Maple, Birch and White Pine trees.
Cap 50-84 mm diameter with the margin striate for ~ 3 mm. Flesh thin, white.
Stipe 7.5 cm long x 1-1.5 cm at apex with a superior pendant annulus, solid.
Spores: 7.6-9.9 × 6.7- 7.9 um; 1.08-1.34 E; !.25 Em
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Good point. I use Largent et al. (HTIMTG-III), too; the quote is taken from p. 101.
I should have mentioned the reason for my comment is that to my knowledge Rod’s spore measurements are taken in side-view. Thus it’s important to be consistent in case the spores cross-section is not round. Other than that, there is nothing wrong with measuring them in face view as long as you indicate so (as per Largent et al.) – actually, it’s much simpler to measure the width accurately, as conventional spores in that orientation are perfectly equilateral.
One other thing is to be aware of tilted spores, i.e., when their longitudinal axis is not perpendicular to the line of sight. This can be confirmed by focusing just in front of and/or beyond a questionable spore — if one end of the spore is more in focus than the other, the spore is tilted. This is especially important for small/short spores as it’s often difficult to assess their tilt in either view, but especially in face-view (cannot see the apiculus well).
I did not know that measurements should be taken in side view, because Largent and Johnson state that they “are usually measured in face and / or side views” but the length of an asymmetrical spore will be the same in side/face views but the width is likely to be different in those views. They do not mention orienting the spores in any particular fashion for measurements to be taken, therefore I always work with a facial view.
Their book was published in 1977. Have microscopic procedures changed (in this regard) since then?
I appreciate your comments and advice.
You may already know this – it’s important to measure spores in the proper orientation, i.e., in profile/side-view, with suprahilar appendage (apiculus) to the side. Usually, the spores are not symmetrical in this view and this detection become a visual cue. In face-view (dorsal or ventral) amanita spores are symmetrical and look the same from either point of view (usually one cannot tell which one, unless you have a good perception of where the apiculus is pointing – up or down).
website and found nothing that matches any closer than A magnivelaris, and even that doesn’t quite fit this profile. Perhaps my measurements are not as precise as they should be. Still have spores and will measure them once more in a few days.
on cuticle and no reaction occurred. Next step will check Amanita website for spore matches. Hopefully will do so Thursday.
I’ll try some KOH tomorrow and post the results. If anyone is interested in this I will gladly mail it to them.
beyond it being a Destroying Angel, I am not sure that I can help you. If you have KOH, you can see if the cap turns yellow. this will also happen w/dried material.
Since you have already measured those spores, you can compare to some of Rod’s spore data, for members of Phalloideaea that occur in the NE, and perhaps get a better idea for a species. Or, it could be unnamed!
I look forward to seeing your findings!
I know very little of color changes in any Amanita section but I did look at some observations of sect. Phalloiseae on MO. Here are a few of them.
MO obs. #s 244828, 250081, 258177, and 286638.
Any ideas. Thanks for your input.
Created: 2017-09-04 23:12:55 CDT (-0400)
Last modified: 2017-09-12 21:48:50 CDT (-0400)
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