390 THE DEUTEROMYCETES (FUNGI IMPERFECTI) 



An appreciation of the origin and modes of development of 

 fruiting bodies among imperfect fungi may be gained from the 

 compilation in Table 4, taken largely from Kempton. 



SPHAEROPSIDALES 



According to Bender (1931), this large order of the Fungi 

 Imperfecti contains 568 genera, 359 of which are in the Sphaerop- 

 sidaceae, 62 in the Zythiaceae, 88 in the Leptostromataceae, and 

 59 in the Excipulaceae. Extensive monographs of this order 

 are not available. The treatise on Phyllosticta by Seaver (1922) 

 is helpful, as are others that deal with special genera, such as 

 Phomopsis, Septoria, and Cytospora. 



Sphaeropsidaceae. Members of Phyllosticta and Phoma are 

 commonly parasitic on seed plants. These two genera are sepa- 

 rated largely upon the basis of the organ attacked, Phyllosticta 

 causing infections on the leaves and Phoma, on the stems and 

 fruits. Distinction of species has been based principally upon the 

 host. Phyllostictina, Macrophoma, and Dendrophoma are struc- 

 turally quite like Phyllosticta and Phoma; all produce discrete 

 pycnidia that arise innately. Some species of Phyllostictina are 

 genetically connected with Guignardia, whereas certain species 

 of Phyllosticta and Phoma have Mycosphaerella as their perfect 

 stage. 



Phyllosticta solitaria, pathogenic to foliage, twigs, and fruits of 

 apple [Guba (1925)], and Phoma lijigam, attacking the stems of 

 cabbage [Henderson (1918)], are not known to possess a perfect 

 stage. 



Coniothyrium is similar in structure to Phyllosticta and Phoma 

 but has colored conidia. The pycnidia of Cytospora and Ceutho- 

 spora are immersed in a stroma, and their conidia are hyahne. 

 Ascochyta has hyaline 2-celled conidia, whereas those of Diplodia 

 are colored and 2-celled. Diplodia zeae, producing a stem and ear 

 rot of corn [Durrell (1923)], is wide-spread and is not known 

 to have an ascigerous stage. Darliica fihnn, with 2-celled hyaline 

 conidia, is of unusual interest because it is a hyperparasite on 

 rusts. 



Species with hyaline, filamentous, several-septate conidia are 

 placed in Septoria, which contains over 1000 species. Among 

 them are such economically important ones as Septoria ly coper- 



