Studies in Mycology No. 7

The genus Blastobotrys v. Klopotek, comprising only one species, is described. The Ascomycete genus Ceratocystis Ellis & Halst. is divided into two separate genera, mainly on account of the morphology of the conidial states: Ceratocystis sensu str. comprises species with Chalara, Chalaropsis and Thielaviopsis conidial states, whereas the majority of species of Ceratocystis auctt. has Sporothrix, Verticicladiellaand Graphium states and is classified in Ophiostoma H. & P. Syd. Four new combinations in Ophiostoma are proposed. The concept of Sporothrix Hektoen & Perkins ex Nicot & Mariat is enlarged considerably. The presence of more or less differentiated conidiogenous cells, conspicuous denticles, and one-celled, hyaline conidia are regarded as diagnostic characteristics. The genus comprises 24 species; most of them are described and depicted. Six species are described as new, and 3 new combinations are proposed; 13 are conidial states of Ophiostoma. One species is excluded from Sporothrix and redescribed in Nodulisporium. A new genus, Calcarisporiella, is described. It can be recognized by the peculiar shape of the conidiogenous cells. Calcarisporium Preuss is restricted to one species, which can be distinguished by erect, verticillate conidiophores and determinate conidiogenous cells. A list of doubtful and excluded species of Calcarisporium is provided