CRONARTIUM 



319 



CRONARTIUM (Fries.) 



Aecidia produced on conifer leaves (so far as known), 

 peridia elongated, aecidiospores in chains. Uredospores pro- 

 duced in a pseudoperidium, brown. Teleutospores i-celled, 



Fig. 96. Cronartium ribicolum. 1, uredo and teleuto- 

 spore stages on leaf of black currant; 2, uredospores, 

 a, and teleutospores, b, cemented together in a column ; 

 3, uredospore ; 4, teleutospores, two of which are germi- 

 nating ; 5, aecidia on bark of Weymouth pine ; 6, 

 aecidiospores. Figs. 1 and 5 nat. size, remainder highly 

 mag. 



aggregated into a column which springs from the sorus of 

 uredospores. 



Weymouth pine rust {Cronartium ribicolum, Deitr. 

 = Peridermium strobi, Kleb.). The aecidium stage of this 



