FUNGOUS DISEASES OF ORNAMENTAL PLANTS. 29 



name the palms that are most affected, many of them becoming 

 blotched more or less with one or another fungus. A tip blight is 

 not uncommon. I have studied the Kentias more than any other 

 palms and will speak particularly of them. If the dying of palm 

 leaves was confined to the tip it might be concluded that the decay 

 was due to the extreme susceptibility of the delicate end of the 

 leaf to untoward influences, but it is not unusual to find circular 

 spots in the bod}^ of the leaf that have the same associating 

 fungus. The tips blight more frequently, possibly, because they 

 are pendent and water collects and is retained there, giving the 

 spores favorable conditions for germination. The fungus found in 

 these blighted tips and elsewhere in the leaves is an anthracnose 

 (^Colectotrichum Kentim Hals.). It is a deep feeding parasite and 

 causes the ruin of the plants or so disfigures them as to forbid 

 their going to market. 



Fungous Enemies in the Orchid House. The royal and fantastic 

 family of orchids is not free from fungous enemies. The 

 Sobralias, for example, are killed outright by an anthracnose 

 (Gloeosporium cinctum B. and C.) that works in the foliage. In 

 like manner the large and tender leaves of the Bletias are preyed 

 upon by several blights that greatly disfigure the plants. In many 

 instances the pseudo-bulbs have large pits of decay due to one or 

 more fungi. Occasionally the large and otherwise superb flowers 

 of vainous orchids are spotted and blotched with brown which in 

 some instances is due to micro-organisms. It is to be remembered 

 that the tissue of the floral part is exceedingly delicate in structure, 

 and also the colors are such that any disease is remarkably con- 

 spicuous. Sometimes the spotting consists of minute specks, in 

 great numbers, scattered over the whole surface of the petal, and 

 so uniform is this that one might' almost conclude at first sight that 

 it was characteristic of that particular species of flower. It is 

 often true that the little specks will be bordered by a delicate ring 

 of pink which will heighten the peculiar appearance of the blighted 

 portion. There may be on the other hand only a single blighted 

 patch, and this, by rapid increase, spreads throughout the whole 

 orchid flower. When a petal is thus attacked it soon becomes 

 worthless and falls down, either remaining attached by its base or 

 drops away entirely. Such patches, upon examination with the 

 compound microscope, reveal the presence of a fungous growth 

 which is well known to the gardener as the gray mould. This 

 gray mould (Botrytis vulgaris) is the most common to be met with 



