176 ILLINOIS ACADEMY OF SCIENCE 



THE GENUS SEPTORIA, PRESENTED IN TABU- 

 LATION WITH DISCUSSION 



Philip Garmaist and F. L. Stevens, University op 

 Illinois 



introduction 



Much difficulty is often encountered in determining 

 parasitic fungi. Large genera which parasitize a large 

 number of host plants are particularly troublesome and 

 often cause those not acquainted with the genus to give 

 up in dispair. Septoria is one of the most troublesome 

 of the larger genera and plainly in need of systematic 

 and morphological study. Such a study will require 

 years of work, but a simple method of listing species 

 according to minimum spore length has been found of 

 great help and is a convenient basis for studies in mor- 

 phology besides affording means for rapid determina- 

 tion. In the following pages the Septoria species de- 

 scribed in Saccardo's Sylloge Fungorum, Vols. 1-22 are 

 listed in tabular form including the more important mor- 

 phological characters together with a list of host plants 

 and localities from which the species are reported. The 

 family of each genus of hosts has been given a number 

 and added to the list. 



characters of the genus 



The characters of the genus Septoria given by Sac- 

 cardo, Lindau and others are essentially as follows : Pyc- 

 nidium, subcuticular, globose-lenticular with a protrud- 

 ing ostiole; maculicole. Spores rod-shaped to filiform, 

 many septate or many guttulate or continuous, hyalin. 

 Basidia none or small. In the main features this de- 

 scription does not differ from that of Rhabdospora, the 

 nearest ally, which is reported as not forming spots 

 or of growing parasitically upon the stems of plants 

 instead of leaves. The property of forming spots or of 

 growing parasitically upon the stems of plants is not a 

 realh^ valid character for the separation of genera. Die- 

 decke,^ therefore, makes the further distinction that the 



iDiedecke Die gatturg septoria. Ann. Myc. 10, 478, 1912. 



