Studies in the Discomycete Genera Crumenula De Not. and Cenangium Fr.

Conifers, especially species of Pinus, may suffer from attack of the Discomycete genus Crumenula. In literature there exist many reports on the “Cenangium disease” of coniferous hosts, but it appears that the apothecia of Cenangium ferruginosum were often confused with the apothecia and even the pycnidia of Crumenula. Cenangium ferruginosum, however, is a common saprophyte. Representatives of both genera were thoroughly studied and an attempt was made to distinguish them even when immature. The asci and ascospores were studied, but special attention was given to the apothecial structure. The study of the latter provided characteristic differences, on the basis of which it became possible to distinguish the species one from another. The necessity arose to transfer the species Crumenula abietina Lgbg. and Crumenula laricina Ettl. to the genus Scleroderris (Fr.) de Not. Cultures of the fungi treated in the present paper were also studied, especially with the aim of investigating the connection between the ascigerous and the imperfect stages. Cultures were made of both ascospores and pycnospores. A conidial form belonging to Crumenula sororia Karst, was newly described as Digitosporium piniphilum Gremmen gen. nov. spec. nov. This form was found in nature and also cultivated in vitro from ascospores. Probably it is a new member of the family of the Excipulaceae. Inoculations were executed with a culture of the ascospores of Crumenula sororia, a mono-pycnosporic culture of Scleroderris abietina and a mono-ascosporic culture of Cenangium ferruginosum. Experiments with Cr. sororia were successful, whilst those with Cenangium always failed.