GOOSEBERRY LEAF CLUSTER-CUPS 



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GOOSEBERRY LEAF CLUSTER-CUPS 



(Puccinia pringsheimiana, Klebahn.) 



During certain seasons the leaves, and sometimes also 

 the fruit, of the gooseberry are studded with little groups 

 of cluster-cups seated on a red or orange patch. When 



Fig. 62. — Puccinia pringsheimiana. ±, portion of a gooseberry leaf 

 witli ttiree aecidia or ' cluster-cups ' fully expanded, X 15 ; 2, section through 

 a single cluster-cup showing, at a, the spores, produced in chains, which 

 afterwards separate into single spores, filling the cup with a yellow powder ; 

 b, the protective wall or peridium ; c, epidermal cells of the leaf ; d, the 

 middle cells of the leaf; e, the mycelium of the fungus running between 

 the cells of the leaf, X300 ; 3, portion of the leaf of a sedge, bearing the 

 sori or minute clusters of uredospores and teleutospores ; 4, a portion of 

 fig. 3, xis times ; 5, teleutospores, X300; 6, uredospores, X300. 



mature the cups have white, torn edges, and are filled with 

 orange spores. The uredo and puccinia forms of the 

 fungus have only quite recently been identified ; they grow 

 on the leaves of sedges {Carex). 



Preventive Means. — As a rule the fungus does not 



