“Smash mount” sounds a lot easier than the “slice on the bias” method I’ve been trying to use to look for cystidia on gill faces. Reading some of the tips for finding cystidia on the gill faces, it seems that there may not be one best method across the board. But smash mount is a good place to begin.
Checking various sources
my manuals and online the color gray is generally mentioned as the expectation for I. fastigiata gills, at least during one maturation stage. Kuo says that I. fastigiata and I. obsoleta are possible synonyms, along with a host of other names.
Another feature of this collection that differs from the classic fatsigiata concept is the lack of giant spores (up to 18 mu in one source) in this collection.