DETAILED ACCOUNT OF SPECIFIC DISEASES OF PLANTS 489 



bases as well, and the mycelium finally grows into the stem killing its 

 tissue which becomes soft and broken down (Fig. 170). The variety 

 known as Mrs. Thomas W. Lawson is especially susceptible. 



Rust {Uromyces caryophyllinus (Schrank). Wint. — This disease 

 was practically unknown in the United States prior to 1890, but now it 



Fig. 170. — Carnation alternariose (AUernaria dianlhi) . i, Branched, septile my- 

 celium; 2, hyphEE below surface of stroma; 3, spore formation; 4, compound spores. 

 5, young clustered hyphEs; 6, older cluster. {After Stevens, F. L., and Hall, J. C; 

 Bot. Gaz., 47: 409-413, May, 1909.) 



is prevalent wherever the carnation is grown commercially. The dif- 

 ferent varieties of cultivated carnations differ to a marked degree in 

 susceptibility. Enchantress and Lawson have a high degree of resist- 

 ance to rust, while Scott and Jubilee are very susceptible. 



