Found on the edge of a trailer. Appeared to have a hollow stem . The cap broke while I handled it.


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The dark/light/dark patterning occurs in several species. In North America, they …
By: R. E. Tulloss (ret)
2017-07-03 08:29:50 PDT (-0700)

often have provisional names and temporary codes. The most commonly mis-used name applies to a Eurasion species (umbrinolutea). In that species, the dark regions are red-brown, and the light region are dirty yellow-tan. In that species, the color pattern also can occur as light/dark/light/dark (with an extra light region in the center). Both patterns can occur in a single fruiting. While we are beginning to find a number of species in the provisional series Penetratrices, the first that were known do not fall into that group. So we cannot be sure whether the present species falls in the Penetratrices simply because the cap is zonate.

In recent days (either on facebook or MO), I wrote about the variety of macroscopic forms that seem to have evolved both in the Penetratrices and in the “remainder” of the Vaginatae. I can’t remember if I mentioned zonate caps in that context. But it would have made that little essay more thorough if had done so.

Last night I ran a sporograph for all the species of Penetratrices for which we have some spore data. It was very enlightening. It emphasized the broad range of “average” shapes for the species in the provisional series…at the moment individual spores range from globose to elongate. As in other amanitas, each species treated alone has a taxonomically useful range of shape and “average” shape.

Very best,


Except for the small size…
By: Dave W (Dave W)
2017-07-03 07:10:04 PDT (-0700)

this reminds me of luzernensis. Color scheme on cap, distinct umbo, and tiny floccose deposits on stipe that appear to not be very dark match this obs 169768. Knowing the form of the basal volva is key. Carefully extracting the mushroom from the ground often allows one to evaluate this trait. Michael, what types of tree(s) are near where this was found?

In the first image, down in the pine leaves, I think I can see fragments of …
By: R. E. Tulloss (ret)
2017-07-02 12:52:34 PDT (-0700)

the universal veil at the bottom of the stem just above the point at which the stem disappears into the ground. Because of this, I think your material could be in the rhacopus/texasorora group.

In the material we have sequenced that originated from Maine, half are rhacopus and none (so far) are texasorora. However, total sample size is only 6. So this is not a terribly good guide to a probably correct ID from an image. Your images don’t look like A. xanthomitra or A. “sp-QUE03”, which are the non-rhacopus options that have come up with in our research on Maine samples morphologically somewhat similar to rhacopus, so far.

Very best,


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