Geranium Diseases 265 



occur in the United States. It was first recorded 

 by Ali Riza * as attacking geranium leaves, causing 

 them to dry and shrivel. 



Broom Rape 



Caused by Orobanche minor J. Esm. 



This parasite is frequently met with on clover in 

 the fields. Its attack on greenhouse geraniums was 

 first reported by Halsted.f The seeds of this para- 

 site germinate in the soil. Soon after its roots be- 

 come attached to those of the geraniums. The 

 growth of the broom rape is soon apparent as a pur- 

 plish, erect stem with scale-like purplish leaves above 

 the ground. Later a number of blossoms are formed 

 along the unbranched stem. The attacked geranium 

 becomes sickly in appearance (fig. 56, b.). Steam 

 sterilization of the soil will kill the seed of broom 

 rape. 



* AH Riza, Bui. Trimest. Soc. Mycol. France, 28: 148-150, 1912. 

 t Halsted, B. D., et al,, New Jersey Agr. Expt. Sta., Twenty- 

 sixth Ann. Kept.: 509, 1905. 



