DISEASES OF GREENHOUSE PLANTS. 273 



spots ultimately become bleached, and the parenclyma 

 dries up. Theu there is the Orchid Anthracnose (Gloeo- 

 sporium Bidgoodii), which causes the ends of the leaves 

 of odontoglossums to become pale, and spots to form on 

 other parts of the leaves. These are about the only two 

 of any consequence. 



Remedy. — Cutting off and burning the diseased leaves 

 seems to be the only one. 



Sclerotinia Disease — This fungoid disease, scien- 

 tifically called Sclerotinia sclerotiorum, attacks a number 

 of plants, including the chrysanthemum. It first appears 

 in the form of a white mould on the stem, just above the 

 soil. As the fungus develops it penetrates the stem, 

 causing it to become brittle and to split, when the interior 

 will be found more or less full of black sclerotia. 



Eemedies. — Fortunately, it is not a very common enemy 

 of the chrysanthemum, but whenever a plant is found to 

 be attacked it should at once be cremated. Should the 

 white mould stage of the fungus be found on the stem, 

 dust freely with slaked lime. 



