Spore print "light-colored": white or buff, sometimes tinged with pink or tan. Greenish and (except for the Russulales) yellow spore prints also go here
Stalk fibrous, not fracturing like a piece of chalk
Fleshhygrophanous (usually all the way through the cap), often with a slightly soapy look and feel to it (wet your finger first to get the full effect)
Spores usually finely roughened, but sometimes smooth
Comments
This is the section most people are interested in, so I've tried to provide a strong selection of species, to try and keep folks from poisoning themselves. Be sure to check that what you have isn't one of those pretty purple cortinarii (see Sericeocybe and Phlegmacium)
I am not totally convinced convinced that these are really separate species: after all, we know that blewits tend to get less purple the longer they grow, and that's the pattern of this taxon: the larger they are, the less purple
This is notSinger's genus Lepista. Singer bases his taxon on spore morphology and color; mine is an artificial one (though perhaps not more so), designed solely to help prevent people from poisoning themselves
Entire fruiting body white at first, becoming pale pinkish buff, except for:
Stalk aging or bruising brown; sometimes swollen at base
In woods, especially under spruce