DILOPHOSPOKA. 479 



Dilophospora. 



Dilophospora graminis Desm. (Britain.) This attacks rye, 

 wheat, and various grasses. Oblong light spots are produced 

 and bear the pycnidia ; when these occur in the flower heads, 

 stunting of the grain takes place. (See also Bilophia, p. 222.) 



2. FAM. NECTROIDEAE. 



The fungi of this family are chiefly pycnidial forms of the 

 Ascomycetes, and as such have already been considered. 



3. FAM. LEPTOSTROMACEAE. 



Htalosporae. 



Leptothyrium. 



Pycnidia black and discoid. Spores ovoid or spindle-shaped, 

 unicellular, and hyaline. 



Leptothyrium periclymeni (Desm.). On living leaves of 

 species of Lonicera. (Britain.) 



L. alneum (L^v.) produces roundish leaf-spots on species of 

 Alnus. (Britain and America.) 



L. acerinum (Kunze) causes spotting of the leaves of Acer 

 campestre and A. platanoides. (Britain.) 



Several other species occur both in Europe and America. 



Melasmia. 



The black pycnidia occupy black extended stromata. Conidia 

 simple and unicellular, borne on rod-like conidiophores. 



Melasmia berberidis Thiim. et. Wint. On living leaves 

 of barberry. Brown spots are produced, bearing the pycnidia 

 as black points ; the spots cause total or partial death of the 

 leaves, frequently ending in defoliation of the shrubs. 



M. empetri Magn. (Britain.) This species was observed by 

 Magnus 1 causing an epidemic disease on crowberry. The 

 symptoms were abnormal elongation of young twigs, and the 

 leaves remained smaller than usual. The rind of the stem was 

 found to be permeated by a mycelium which produced black 



^ Berichte d. deutsch. botan. Gesell., 1886. With illustrations. 



