The Bolete Filter is a triage (A Synoptic Key) for North American Boletes developed by Scott Pavelle with lots of input from other club members and country wide experts and hosted by the Western Pennsylvania Mushroom Club.
Tradition creates some kind of “dichotomous” key to identify particular mushrooms. For example, you might start with a particular type of stem feature, and then branch off from there by asking various on-off questions about subsequent features. The problem is, what do you do when the stem has been damaged or it isn’t clear what category it belongs to? Once you lose your place in a dichotomous key it is impossible to go any further.
The Bolete Filter approach uses a “synoptic” key, which allows you to limit the number of possibilities by applying whatever features seem to be clear. If the stem features aren’t clear, start with things like the cap color, flesh color, region, and staining characteristics. It’s extremely hard to create a synoptic key on paper because you need to start with a grid listing every possible answer, and then create a transparency for every characteristic you want to use as a filter.
If you find a bolete and are not sure if it is edible or even which species it is please give the Bolete Filter a try.