GOOSEBERRY DISEASES 227 
EUROPEAN CURRANT-RusT 
Caused by Cronartium Ribicola Fisch. von Wald. 
The European currant-rust, or white pine blister-rust, is 
known to occur on the gooseberry, although it is notably less 
common on this plant than on the currant. The characteristics 
of the disease on the gooseberry may be understood by reading 
the account as presented under Currant, page 212. 
Ciuster-Cup Rust 
Caused by Puccinia Pringshetmiana Kleb. 
The cluster-cup rust is exceedingly common on wild goose- 
berries and currants and is known to some extent on cultivated 
forms. It occurs in Europe, Alaska and in many parts of the 
United States. Serious damage is seldom reported, although 
some complaint was made several years ago (1892) of the loss 
of foliage and fruit on account of an unusual outbreak. 
Symptoms. 
The disease may be recognized in the early summer by the 
presence of bright, orange-colored cups grouped on reddish, 
swollen areas on the lower surface of the leaf. Sometimes these 
structures are found on the fruit, causing distortions. 
Cause. 
The cluster-cup rust fungus is Puccinia Pringsheimiana. The 
orange-colored cups already described contain spores known 
as eciospores. These are carried to various common sedges, 
Carex acuta and C. Goodenovii, where infection takes place. 
Following the development of the mycelium within the sedge 
leaves, a second type of spore structure, known as a uredineum, 
is produced; the uredinia bear uredospores. Later a third 
kind of fruiting body appears; this is known as a telium, and 
it bears teliospores. In the latter condition the winter is 
