The volva disintegrated when I dug it up. I googled Rod Tulloss and found this site: http://pluto.njcc.com/~ret/amanita/ ; it is one of the most impressive shroom sites I’ve run into. If he says we don’t have vaginata here I’ll happily scratch it off my list and go with your suggestion.
Did you dig it up? The gray lining to the volva indicates constricta, and to further muddy the myco-waters, Rod Tulloss claims that we don’t get vaginata here anyway. We have a confusion of grisettes here on the West Coast and naming them can get difficult. It’d be a “nice” masters thesis for somebody, but don’t look at me. I have enough troubles!