Morphological variation and cultural characteristics of Coniothyrium leucospermi associated with leaf spots of Proteaceae

During an examination ofConiothyrium collections occurring on Proteaceae one species,C. leucospermi, was repeatedly encountered. However, it was not always possible to identify this species from host material alone, whereas cultural characteristics were found to be instrumental in its identification. Conidium wall ornamentation, which has earlier been accepted as crucial in species delimitation is shown to be variable on host material, making cultural comparisons essential. Using standard culture and incubation conditions,C. leucospermi is demonstrated to have a wide host range in the Proteaceae. In addition, microcyclic conidiation involving yeast-like budding from germinating conidia and hyphae in culture is newly reported for this species.