334 THE RUSTS OF NOVA SCOTIA. PHASER. 



species, but no injury to the latter plants has been reported 

 from Nova Scotia. Control measures would be the destruction 

 of the affected parts in the fall before the dispersal of the 

 spores. 



The "'Orange Rust" of the raspberry and blackberry 

 (Gymnoconia inter stitialis} is a serious pest in some parts of 

 the United States, attacking the cultivated species. As far 

 as reported it is confined to wild species in Nova Scotia. The 

 mycelium is perennial so that to combat this rust the diseased 

 plants should be dug up and burned. 



The aecial stage of a sedge rust sometimes occurs on the 

 fruit of the cultivated gooseberry. This stage usually passes 

 under the name of Aecidium grossulariae. It is probably not 

 common enough to call for control measures, which would be 

 the destruction of the sedges in the vicinity. 



Rusts of the Cereals: A few collections of corn rust have 

 been made, but it is not usually common enough to cause any 

 serious injury and has not received much attention. 



The black or stem rust (Puccinia graminis) attacks wheat, 

 oats, barley, rye and many grasses. It has a world wide 

 distribution and does immense damage to the grain crops. 



It does not seem to be very common about Pictou, but in 

 some parts of the province it is abundant and must cause 

 much injury to the oat and wheat crop. It can be recognized 

 by the black uncovered telia which are usually found on the 

 stem, though they may occur on the leaves and sheaths. 



The aecial stage is on the barberry, but this shrub is not 

 common enough to explain its appearance year after year. It 

 is probable that the barberry has little to do with the rust in 

 Nova Scotia, and that the aecial stage is usually omitted. The 

 uredospores live for some time and have been shown to sur- 

 vive the winter even in cold climates. Another theory is that 

 the uredospores are carried from more southern countries, 

 where they survive the winter, by the wind, and thus the spring 



