1917.1 PUBLIC DOCUMENT — No. 31. 59a 



DEPARTMENT OF BOTANY. 



A. V. OSMUN. 



With certain additions, the activities of the department have 

 continued along lines previously reported. Work which may be 

 considered as public service, including plant disease diagnosis, 

 seed work, and correspondence pertaining to these and a great 

 variety of other botanical matters, has increased to a consider- 

 able extent. As pointed out in the last annual report of the 

 writer, this work seriously interferes with research, and it is 

 hoped that the time may not be long postponed when extension 

 service funds will be available to care for it. 



As in previous years, plant disease work has occupied the 

 greatest amount of attention. Reports of diseases new to the 

 State have been few, but a number of unusual diseases ap- 

 peared, and some others commonly present in minor degree 

 were widespread, and particularly severe in their outbreaks. 

 Diseases not previously noted in the State are a vine blight of 

 Aristolochia, caused by an undetermined species of Gloeosporium, 

 and an anthracnose of English elm, caused by Glceosyorium in- 

 consyicuum Cavr. The former disease was not uncommon 

 during the summer, but in all cases noted, save one, little 

 damage was done. In the one case a very large vine was com- 

 pletely defoliated, and practically all new shoots became black- 

 ened and died. 



An unusual number of shade-tree diseases caused by species 

 of Gloeosporium were noted. Trees on which such diseases were 

 observed included sugar maple, Norway maple, white oak, red 

 oak, sycamore or plane tree, beech, American elm, English elm 

 and Lombardy poplar. Prehminary work, including a limited 

 number of cross inoculations, leads the writer to suspect that 

 the same fungus may be responsible for several of these dis- 

 eases, but positive proof has not been established. 



