220 FUNGOID PESTS OF CULTIVATED PLANTS. 



with a colourless rough coating, and orange contents (17-24 x 15-17 u). 

 Paraphyses clavate (40-60x15-20 /.i). 



Teleutospores forming small brown crusts, cylindrical, cohering 

 laterally, and truncate at the apex (50 x 10 /i), of a brown colour. 



Has been recorded for France and Germany. 



Sacc. Syll. vii. 2112 ; Flour. Brit. Ured. p. 241. 



Black Poplar Rust. 

 Melampsora populina (Jacq.), PI. XXI. fig. 36. 



This endophytal parasite occurs commonly on the living leaves of 

 Populus nigra, balsamifcra, and italica. It has been affirmed that the 

 cluster-cups are to be found on the Clematis, but this has not been 

 confirmed by those whose unbounded faith rests upon artificial cultures. 



The pustules of the uredo are found on the under surface, are roundish, 

 and at first covered by the epidermis, brown. The uredospores are 

 elongated elliptical, or ovate, and rough (28-40x15-20 /u), of an orange- 

 yellow colour, mixed with capitate paraphyses. 



Teleutospores in flat pustules, generally crowded and often confluent, 



forming reddish-brown and then blackened crusts. The spores are 



cylindrical, closely packed side by side, and angular by compression, so 



that they are polygonal in section, a little attenuated downwards (40-50 



x 10-15 /u), pale brown in colour. 



Known also in France, Belgium, Netherlands, Germany, Finland, 

 Bohemia, Austria-Hungary, Switzerland, Italy, Portugal, Asiatic Siberia, 

 and North America. 



.Sacc. Syll. vii. 2113 ; Plowr. Brit. Urcd. p. 242 ; Cooke, Hdbk: No. 

 1561 ; Cooke, M.F. p. 219, figs. 195, 196. 



Poplar-leaf Blister. 

 Taphrina aurea (Fr.), PI. XXI. fig. 37. 



This blister on Poplar leaves has long been known on Populus nigra, 

 forming roundish blisters, which are convex on the upper surface and 

 concave beneath, where they acquire a golden-primrose appearance. The 



; are clavate, attenuated at the base, and truncate at the apex (92-100 

 x 10 25 //). The sporidia are globose (4 n broad). 



Tin same fungus, apparently, produces pocket-like growths on the 

 ovary of Populus tnmula and P. alba (II. & S. fig. 74). 



Known also in Fiance, Germany, Sweden, Finland, and Italy. 



Sacc. Syll. viii. 8826 ; Sacc. F. Ital. fig. 1281 ; Hart. & Som. Dis. 

 Trees, p. 135, figs. 73, 71 ; Mass. I 'I. Dis. p. 91. 



Another blister | Taphrina Johamonii, Bad.) attacks the carpels of the 

 Aspen, causing them to swell and become of a bright golden-yellow. Not as 

 determined to lie British, unless it proves to be the above form of 

 Tapht inn aurea. 



Muss. P . Dis. p. !»2. 



Tin Lombardy Poplar is attacked by I > ill umospharia populina, which 

 produces a disease met with in many parts of France and Germany. 

 Hart. & Som. Dis. Trees, p. 101. 



