30 MASSACHUSETTS HORTICULTURAL SOCIETY. 



upon old Ijlooms in greenhouses or other warm, moist places, and,, 

 abounding in spores which are borne upon the tips of slender 

 threads, it keeps the atmosphere well stocked with germs, and 

 these falling upon the delicate tissue of the orchid bloom will 

 induce decay. 



As a precautionary measure it goes without further saying that 

 any and all old and worthless parts of greenhouse plants that are 

 harboring this gray mould, or in fact any fungous growth, should 

 be promptly removed from the place and consigned to the furnace. 

 In this way a large portion of the decay of petals and other floral 

 parts will be obviated. 



Botrytis is able to gain a foothold within the vigorous leaves^ 

 particularly when some petal or other floral organ already infested 

 with the graj^ mould falls upon the leaf and remains there. The 

 fungus therein spreads from the petal to the leaf and shortly a blotch 

 is formed upon the leaf, which continues to spread for some time, 

 and possibly the decaying leaf in falling upon another will continue 

 to spread the disease. 



Fungous Diseases of Variegated Plants. Many of the indoor 

 foliage plants are subject to blights of various sorts, but limited 

 time will permit only a word under this head. It may be stated 

 as a general principle that variegated foliage is more subject to 

 attacks from fungi than the ordinary green leaves of plants of the 

 same species. Thus the Ficus elastica var. variegata, while it 

 may possess added attractions on account of the lack of chloro- 

 phyll, for the same reason is more susceptible to blights than the 

 ordinary plants. Variegated Pelargoniums are apt to suffer from 

 fungous attacks while the green leaved sorts go free. In like 

 manner the day lilies, like the Funkia undulata var. variegata, are 

 often worthless, and in such plants as the Aspidistras, where large 

 white stripes run through the leaves, the fungi are much more apt 

 to attack the etiolated parts. In short, gardeners are getting shy 

 of variegated plants, because such have an evident tendency to 

 blight. 



Fungi of the Seed Bed. Passing now to the nursery department 

 of the plant establishment, we find the seed bed is not exempt 

 from fungous enemies. The leading trouble passes under the 

 common name of "damping off," which is a general expression for 

 a failure of the seedlings to maintain a stand. There may be 

 many reasons for a failure at this point, but the chief one is the 

 presence, in the tender tissue of the young sprouts, of microscopic 



