These keys attempt to include all taxa that are in use in contemporary literature (roughly since the mid 1960?s). This is an on-going project; the keys are not meant to serve as final word on the determination of a specimen or to be considered formal publication. I recommend that all determinations be followed up by consulting published taxonomic works or verification by an expert in Caliciales taxonomy.

Although the old Caliciales is an invalid phylogenetic group, most taxa that formed the group important characters that unite them ecologically. Most have stalked ascomata with loose spores remaining at the top (either a mazaedium or spores piling up after active, but weak discharge). This structure suggests similar spore dispersal mechanisms. Also most taxa from the Caliciales occur in one of two specific types of habitats: (A) on twigs, usually with very strong host specificity, and (B) in sheltered sites on old wood or bark. Some of the remaining genera utilize both habitats. For example in the lichenized genus Calicium, C. adaequatum inhabits twigs of a selection of hardwood trees and shrubs, while other species in the genus inhabit sheltered sites, particularly on old wood or bark; similarly in the Mycocaliciaceae, Stenocybe pulatula inhabits twigs of the hardwood genus Alnus, while Stenocybe clavata inhabits old bark on conifers. Thus the old group may be retained by ecologists as a functional group, the „calicioids?.