BLACK RUST OF GRAIN (PUCCINIA GRAMINIS) 399 



FIG. 356. Stage of the Wheat Rust on the Barberry bush, Berberis 

 vulgaris. Left, leaf of Barberry, showing the affected areas which are red- 

 dish, much thickened, and contain many cup-like depressions; right, a very 

 much enlarged section through the affected area of the leaf, showing one of 

 the cups (c) with chains of aecidiospores ( X 200) . The very small spores at 

 (p) are the spermatia or pycniospores. 



FIG. 357. Diagram showing the life cycle of the Wheat Rust. A t 

 wheat plants; B, barberry bush; u, uredospore; t, teleutospore; s, basidio- 

 spores; a, aecidiospore. 



