Ornamental Plants 413 



flower or its stalk are similarly diseased. Through the corm 

 the roots are reached. Here the skin is unaffected and re- 

 mains as a parchment-like tube filled with the creamy residue 

 of decay. Rot of the bulb may be arrested by unfavorable 

 conditions and show only as dark sunken spots. 



The course of the disease extends from a few days to several 

 weeks, or the disease may lie dormant for months, even 

 from season to season. Such cases of dormant disease carry 

 the infestation to the succeeding crop and in commercial 

 corms from country to country. The rot spreads rapidly 

 from plant to plant by way of the diseased roots and through 

 the soil itself. The causal bacillus remains in the soil and may 

 attack healthy corms planted therein at later periods. 



No known treatment of diseased plants is practicable. 

 Infestation of soil may be prevented by careful inspection 

 of all corms so as to avoid diseased ones. It is best to test 

 commercial corms in pots to be assured of their healthful- 

 ness before putting them in the beds. All soil from badly 

 infested beds should be disinfected or removed and fresh 

 soil supplied. 



Leaf-spot {Phijllosticta richardice Hals.). — Blighted leaves 

 bear large ashen spots upon which are numerous minute dark 

 pycnidia. 



Another Leaf-spot due to Cercospora richardicecola Atk. 

 was first mentioned by Atkinson in 1891 as occurring in Ala- 

 bama. The edges of the leaves turn black in circular spots. 



CAMELLIA 



Sooty-mold (Capnodium sp.). — The sooty -mold is perhaps 

 more injurious on this plant than on any other ornamental, 

 not as an actual disease but by injury to salability of the foli- 

 age. Leaf-spot (Pestalozzia guepini Desm.) is common. 



CANNA 



Rust (Puccinia cannce (Wint.) P. Henn.). — This true rust 

 is common and injurious in the warmer climates but is rare 

 in the more temperate regions. 



