JUNIPER DISEASES 203 



masses break through the bark as orange-yellow hemispherical 

 pustules about an eighth of an inch high. The alternate hosts 

 are quince, apple and species of service-berry and haw. 



In northeastern United States and westward to Wyoming and 

 Colorado, the dwarf juniper, and Juniperiis sibirica are affected 

 by Gymnosporangium clamria^orme (Jacq.) DC. The branches 

 of all sizes are attacked and slightly swollen for several inches. 

 Spore-horns are produced in alDundance in the spring from 

 the swellings. They are brownish yellow and about one-half 

 inch long. The alternate stage of this rust is produced on 

 quince and species of service-berry. 



Along the Atlantic Coast the red juniper is attacked by Gym- 

 nosporangium effusum Kern. Long slender enlargements of 

 the smaller branches less than an inch in diameter are pro- 

 duced. This fungus also causes swellings on the trunks. 

 The spore-masses are wedge-shaped and often as large as one- 

 half inch high by a quarter of an inch long at the base. The 

 alternate host for this species is unknown. 



Several species of juniper in Colorado, New Mexico and Ari- 

 zona are attacked by Gymnosporangium gracilens (Peck) Kern 

 and Bethel. Long spindle-shaped swellings of the branches are 

 formed. The spore-masses break through the bark in long rows 

 and are about an eighth of an inch high. Species of Fendlera 

 and Philadelphus are alternate hosts of this rust. 



In the region extending from northeastern United States to 

 Colorado and Wyoming, the red juniper and Juniperus sibirica 

 are attacked by Gymnosporangium cornutum (Pers.) Arthur. 

 The smaller woody branches are slightly enlarged. The spore- 

 masses are flat or cushion-like and not extensive. Mountain 

 ash is the alternate host. 



In a restricted region in Kentucky and Missouri, the red 

 juniper is attacked by Gymnosporangium exterum Arthur and 

 Kern. Short spindle-shaped swellings are produced and the spore- 

 masses in the spring are flat and anastomosing. The alternate 



