Since the genus Ascobolus was established in 1791, several more genera of Ascobolaceae with coloured ascospores became known, each with a fair number of species. Some species previously described in other genera were later recognized to belong to the Ascobolaceae and a large number of new species, subspecies, varieties and forms have been described through the years. Numerous species of Ascobolus have been described as new simply because the same fungus was found on a different substratum or because its asci opened by an operculum. Others were described several times under different names because of the lack of a complete survey and inadequate knowledge of specific variability. This has also led to many erroneous interpretations and identifications.