ORNAMENTAL PLANTS 465 



bands, at the same time becoming brittle and often 

 breaking away. Diseased leaves should be burned and 

 the plants sprayed with Bordeaux mixture or ammoniacal 

 copper carbonate. 



Glomerellose {Glomcrella rufomaadans (Berk.) Spaul. & 

 von Schrenk var. cyclaminis Patt. & Ch.).* — The spots on 

 the leaves are circular, watery, with definite borders. Black 

 hairy acervuli are often present in great numbers. 



DAHLIA 



Powdery mildew {Oidium of Erysiphe communis Wallr.). 

 — This powdery mildew is quite common, affecting par- 

 ticularly the lower leaves late in the season. 



Phomose (Phoma Dahlice Berk.). — The stems of the 

 flowers are the chief seats of attack. The flowers are 

 small and are often dropped before opening. 



DRAC.ENA 



Phyllostictose (Phyllostida maculicola Halst.). — This 

 may be recognized as small, brown, somewhat angular 

 spots on the leaves, each spot surrounded by a rather 

 wade yellow border. Minute pycnidia are present. 



FERNS 



Phyllostictose, blight (Phyllosticta pteridis Halst.), — The 

 tender growing tips of ferns are subject to blight, and 

 blighted spots may also occur lower upon the leaf. The 

 l)rown dead tips and leaf spots bear minute pycnidia. 

 Blighted parts should be cut away and burned and the 



' Patterson, Mrs. Flora, and Charles, Vera K., U.S. Dept. Agr. Bur. 

 Plant Indus. Bui. 171. 

 2h 



