Cytology of the Ascus of Claviceps Phalaridis

SUMMARY

In Claviceps phalaridis, a species that almost certainly belongs in the Balansiae, croziers give rise to asci by the method typical of higher Ascomycetes. The haploid chromosome number is tentatively considered to be five or six. The ascospores are filiform and uninucleate when first formed. Three nuclear divisions occur within the ascospores, and each mature ascospore consists of eight uninucleate cells. Each cell of an ascospore may give rise to a single, septate conidium borne on a short, septate conidiophore while the ascospores are still within the ascus. Production of conidia by this method is not known in other fungi.