ORNAMENTAL PLANTS 457 



of the plant is also recommended. The leaves should be 

 kept as free from moisture as possible by free ventilation, 

 and still better by subirrigation. 



Fumigation of the houses in the fall before the introduc- 

 tion of the plants serves to lessen infection from old spores. 



Septoriose {Septoria Dianthi Desm.). — The spots of this 

 disease — usually upon the leaves, sometimes upon the 

 stems — are circular or oblong, blanched or pinkish, and 

 purple bordered. Numerous small black pycnidia lie in 

 the central region. The disease is especially abun- 

 dant upon the lower portion of the leaves and the 

 sheaths. The diseased part often becomes contracted, 

 which results in bending and curling of the leaves. Sur- 

 face watering of the plants or humid atmosphere tend to 

 increase the trouble. 



Venniculariose {Vermicularia mheffigurata Schw.). — The 

 bases of the leaves or the stems are usually the points of 

 attack. Black spore-bearing bodies appear in abundance. 

 Spraying with ammoniacal copper carbonate has given 

 good results. 



Altemariose (AUernaria Dianthi^ S. & H.). — This leaf 

 and stem disease has been reported as quite troublesome 

 in Connecticut, Pennsylvania, District of Columbia, and 

 North Carolina. It consists of spots mostly upon the 

 leaves, sometimes upon the stems, especially at the nodes. 

 These are strikingly characteristic, of ashen whiteness, 

 with the centers occupied by an often scanty, though 

 sometimes profuse, black fungous growth. The diseased 

 spot is dry, somewhat shrunken, thinner than healthy 

 portions of the leaf, approximately circular, though often 



1 Stevens, F. L., and Hall, J. G., Bot. Gaz. 47, 1909. 



