158 ILLINOIS ACADEMY OP SCIENCE 



The type of the genus is 



Gloeodes pomigena (Schw.) nov. comb. 



Dothidea pomigena Schw., Trans. Am. Phil. Soc. n. s. 

 4:232,1832. 



Aster oma pomigena (Schw.) fide Curt, in Sprague, 

 Proc. Boston Soc. Nat. Hist. 5 :325, 1856. 



PhyllacJiora pomigena (Schw.) Sacc, Syll. Fung. 5:622, 

 1883. 



Leptotliyrium Pomi Selby, Ohio Agr. Exp. Sta. Bui. 

 121 :12, 1900, as to sooty blotch only, the original idea of 

 L. Pomi having reference to the fly speck fungus alone. 



Pycnidia dark brown, dimidiate, scattered or aggre- 

 gated, superficial, rupturing irregularly; conidia oblong, 

 sometimes slightly curved, one-celled, hyaline, 10-20 x 

 4-7/A ; conidiophores short or lacking ; paraphyses septate, 

 gelatinous, slender, blunt, longer than the conidia. 



Hab. fruits and stems of certain species of Pyrus. 



Host Considerations. Sooty blotch of pomaceous 

 fruits is very common on the apple, Pyrus Mains L. (Fig. 

 2), appearing less often on the pear, Pyrus communis L. 

 (Fig. 5). The literature available does not record with 

 certainty, the occurrence of sooty blotch on any other 

 hosts. Duggar (1909) reports what was either sooty 

 blotch or fly speck on trees and shrubs other than 

 pomaceous ones, though he does not mention any host 

 plant by name, nor does he distinguish betAveen sooty 

 blotch and fly speck, because he regarded them as identi- 

 cal. 



The writer has observed a sooty blotch on the twigs 

 or stems of peach, Prunus Persica (L) Stokes, and black- 

 berry, Rubus nigrobaccus B. (Fig. 19), both of the 

 family Rosaceae, and on black mustard, Brassica nigra 

 (L) Koch. (Fig. 20), of the family Cruciferae. 



Various authorities regard the Rhode Island Greening, 

 Peck's Pleasant, Rome, Baldwin, and Northern Spy ap- 

 ples, and Anjou, Lawrence, and Kieffer pears as those 

 on which the fungus is most commonly found in North 

 America. English Avriters report the Newton Wonder 

 apple and Catillac pear, as most frequently bearing the 



