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. Teleutosp'ores i -celled, 



FIG. 96. Cronartium ribicolum. i, 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, i 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 



