222 FUNGOID PESTS OF CULTIVATED PLANTS. 



CRACK WILLOW RUST. 

 Melampsora epitea (Kze.), PL XXI. fig. 41. 



This parasite on the leaves of Salix viminalis is at present without 

 any accredited cluster-cups. The uredo is generally found on the under 

 surface, in minute orange powdery pustules. The uredospores are 

 globose, rarely somewhat elliptical, rough, and pale yellow (20 p diam.), 

 mixed with numerous clavate paraphyses. 



Teleutospores also on the under surface, very small, at first brown, 

 then nearly black, crowded and somewhat hemispherical, and compact. 

 Spores cylindrical, pale brown (30-34 x 12-14 /*) and smooth, with a 

 thick coat. 



Recorded also in France, Belgium, Germany, Italy, and Asiatic 

 Siberia, probably in North-Western India. 



This species is also said to be found on Salix alba, S. incana, 

 S. purpurea, S. nigricans, and S. retusa. 



Sacc. Syll. vii. 2108 ; Plowr. Brit. Ured. p. 239 ; Sow. Fung. t. 398, f . 1 ; 

 Cooke, Hdbk. No. 1558, pp. 



GOAT WILLOW RUST. 

 Melampsora farinosa (Pers.), PI. XXI. fig. 42. 



The final stages of this rust are found on the leaves of Salix Caprea, 

 cinerea, aurita, and reticulata ; it was formerly known as Melampsora 

 salicina, and although it has been suspected that the cluster-cups would 

 be found on the leaves of Euonymus, it has not been demonstrated. 



The uredospores are found on the under surface in roundish pustules, 

 which are either scattered or clustered together, sometimes in a circular 

 manner, powdery, and of an orange colour. The spores are more or less 

 globose, rough, with a hyaline coat and golden - orange contents 

 (17-22 x 13-15 p), mixed with numerous clavate paraphyses. 



The teleutospores occur on the upper surface, covered by the epidermis, 

 in clusters which are often confluent and form thick flat crusts, which 

 are -at first orange, then brown, and at length nearly black. The spores 

 are cylindrical, slightly narrowed downwards, and closely packed side by 

 side (40-45 x 16-17 p), pale brownish. 



Found also in France, Belgium, Germany, Finland, Austria, Switzer- 

 land, Italy, Asiatic Siberia, and North America. 



This appears to be the same as Melampsora Caprearum. 



Sacc. Syll. vii. 2106 ; Plowr. Brit. Ured. 238 ; Cooke, Hdbk. No. 1558 ; 

 Cooke, M. F. p. 219, figs. 191, 192. 



WILLOW-LEAF BLOTCH. 

 Rhytisma salicinum (Pers.), PI. XXI. fig. 43. 



This blotch in some respects resembles that which is so common on 

 Sycamore and Maple, forming large, thick, pitchy-black blotches on the 

 leaves of the Goat Willow, Salix Caprea, and several other species. 



The early stage, whilst the leaves still remain attached to the tree, is 

 known as Melasmia salicina and is the conidial condition. The blotches 



