WILLOW LEAF-BLISTER. 



485 



8. Melampsora Harticfii, Thiim. 



(Willow Leaf-blister.) 

 a. Description and mode of Attack. 



On the leaves of several species of willow, and especially on 

 their under surface and the ends of their young shoots, little 

 golden -coloured 

 cushions, subse- 

 quently turning 

 brown and then 

 black, may appear 

 at the end of May 

 or the beginning of 

 June. Leaves which 

 have been attacked 

 soon become marked 

 with black blotches 

 and fall off; the 

 badly infected shoots 

 also die from their 

 tips downwards. 

 The sporonarps hi- 

 bernate on the dead 

 leaves lying on the 

 ground and produce 

 p r o m y c e 1 i a and 

 sporidia in the 

 spring, the spores 

 from which spread 

 the malady by ger- 

 minating on fresh 

 leaves and shoots. 



The same disease 



infects species of Ribes (currant or gooseberry plants), as 

 Caeoma Ribesii, Link., but this intermediate stage is 

 unnecessary in the life of the fungus. 



Fig. 1%1Salix acutifolia, Willd., attacked by 



Melampsora Hartigii. 

 a Green leaf with oraiige yellow sporocarps. 

 I Leaves with black patches, withering. 

 c Sporocarps on the epidermis of the stem. 



