10 SOME FUNGOUS DISEASES OF ECONOMIC IMPORTANCE. 



does not always bear a constant relation to its host, as sometimes 

 the leaf enfolds the fungus without the leaf tissue being intermingled, 

 or frequently isolated fibrovascular bundles are seen embedded in the 

 stroma. Apparently this condition is produced by the fungus early 

 attacking the parenchyma of the young leaf and finally appropriat- 

 ing all of the parenchymatous tissue, thus leaving the bundles in a 

 stranded condition. This process was clearly observed in cross sec- 

 tions, which also showed secondary conidia of the fungus in early 

 and successive stages of growth. Numerous sections were made in 

 order to discover if the mycelium ran down in the stem tissue, but 

 no evidence of such a fact could be found. 



DESCRIPTION OF THE FUNGUS. 



When fully developed the parasite somewhat resembles the sclerotia 

 of Clarice ps purpurea. These sclerotia-like bodies originate at the 

 nodes, are generally sessile, and probably none exceed a centimeter 

 in length. Their color when young could not be determined, as the 

 specimens were mostly mature, and in that stage are dark green or 

 black. A microscopic examination of the fungous body showed it to 

 consist of a central, hyaline sclerotia-like tissue, in which are many 

 large, round conidial chambers. 



Perithecia are developed from the peripheral layer, mostly scat- 

 tered, seldom more than two near together. The outer surface of 

 the fungus has a more or less velvety appearance, due to the loose, 

 dark-greenish peripheral hypha?, bearing Cladosporium-like second- 

 ary conidia. 



DISCUSSION OF RELATED FORMS. 



Many difficulties were encountered in establishing the systematic 

 position of this fungus on account of its unusual combination of 

 characters. The writers have thought best to class it with Hypo- 

 creaceaB in the section Phragmosporse. 



An exhaustive search was made of the literature available to the 

 United States Department of Agriculture for a fungus on any bamboo 

 having the characters of the one now being described, but none 

 could be found to which this could be referred, and but one species 

 seems to have been reported as producing a comparable effect on its 

 host. This other fungus causing witches'-broom of a bamboo is de- 

 scribed by Dr. I. Miyake under the name Aciculosporium take in the 

 Botanical Magazine of Tokyo, August, 1908. Doctor Miyake states 

 that the disease occurs in Japan, possibly coming from China, Korea, 

 or India, but that it probably does not occur in Europe, as there is 

 no report concerning its presence there. The article is in Japanese, 

 and when the name Aciculosporium, the only English word, was 

 seen it was thought Doctor Miyake's fungus was located, as that name 



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