220 



rUXGI AND rUXGICIDES 



Like yarious other members of the famih' of rusts 

 to which this fungus belongs, it exists in three distinct 



FIG. 90. CLOVER RUST. 



c, Cluster-cups aud jecidimn spores; d, uredo spores ;/, uredo pustule on clover 

 leaf: e. teleuto spores: rj, cross-section of stem showing mycelium between 

 cells; also two teleuto spores and one uredo spore. • 



successive stages. Early in the season it appears — prin- 

 cipally upon white clover j^lants — in the so-called cecid- 



