28o DISEASES OF CULTIVATED PLANTS 



Pseudopeziza ranunculi (Sacc.). Ascophores in groups or 

 scattered, on the under surface of Ranunculus repens and 

 other buttercups. Spores oblong-clavate, at length i-septate, 

 15-16x6-7 /*. 



Pseudopeziza cerastiorum (Fckl.). Gregarious on leaves of 

 various species of Cerastium. Spores cylindric-oblong, con- 

 tinuous, 9-12X3 /*. 



Pseudopeziza calthae (Mass.). Gregarious on brown spots 

 on under surface of leaf of Caltha palustris. Spores con- 

 tinuous, narrowly elliptic-oblong, 15-20X6-8 p. 



Pseudopeziza radians (Sacc.). Gregarious, often forming 

 black patches or straight-radiating or dendritic lines on both 

 surfaces of leaves of Campanula patula, C. rapunculus, and 

 other species of Campanula. Spores continuous, nearly 

 cylindrical, 8-10X3-3*5 /*. 



Pseudopeziza repanda (Sacc.). Gregarious on the under 

 side of leaves of Galium boreale, G. mollugo, Asperula odorata, 

 and other allied plants. Sometimes present on stem also. 

 Spores continuous, narrowly clavate, 10-13 X 2*5-3 //,. 



It is suspected, but not definitely proved, that a minute 

 fungus called Placosphaeria stellatarum (Sacc.) found on living 

 leaves of Galium and Sherardiae^ is a conidial form. Minute 

 black stromata on both surfaces of the leaf, with numerous 

 minute internal cavities containing rod-shaped, hyaline 

 spermatia, 30-40 X 1*5-2 p. 



A second form also suspected of affinity, is called Phyl- 

 lachora punctiformis (Fckl.), the spermatia are cylindrical, 

 hyaline, 6 x i *5 /^. 



DASYSCYPHA (FRIES.) 



Cup minute, nearly or quite sessile, externally pilose or 

 downy ; asci 8-spored ; spores elongated, hyaline, continuous 

 or i-septate; paraphyses cylindrical or lance-shaped. A 

 conidial form is present in some species, under the form of 

 minute whitish pustules. 



A large genus, most are saprophytes, a few closely allied 

 species are very destructive parasites on conifers. Charac- 

 terised by the villose or downy exterior of the cup, and by 

 growing on plants. 



Larch canker. This very destructive disease, caused by 

 Dasyscypha calycina (Fuckel), in some books called Peziza 



