Some authors have called the possibility of an association to Vaccinium and my own observations confirm the proximity of Vaccinium ovatum (Huckleberry) in almost all collections. The degree of pale/bluish tinges on the stem/gills is a variable characteristic. The strong tendency of the stipe to develop girdles (like C. trivialis)  helps to separates it from the very similar 2--needle Pine species: C. mucosus. These three closely related species are members of Section Myxacium in Subgenus Myxacium, which molecular studies have shown to be monophyletic. All three have large, coarsely verrucose to wrinkled spores.