224 FUNGOID PESTS OF CULTIVATED PLANTS. 



Pine Cluster-cups. 

 Pcridcrmium Pini (Wallr.), PI. XXI. fig. 46. 



These peculiar cluster-cups are found on the leaves and young branches 

 of Pinus sylvestris, in about May and June. Those on the leaves differ 

 somewhat from those on the branches ; the former are scattered or in 

 small groups, and are cylindrical or compressed laterally. The mouth is 

 torn irregularly (2-2^ mm. high). Those on the young twigs form swell- 

 ings, from the presence of the mycelium the cups are larger, crowded, 

 whitish, with the mouth spreading and much torn (5-6 mm. broad). 

 The a^cidiospores are spherical or angular by compression, of an orange 

 colour, and coarsely and thickly warted (30-40 x 18-80 /<). 



The remaining stages of this parasite are affirmed to be passed upon 

 the leaves of different species of Ragwort, as Senecio vulgaris, viscosus, and 

 Jacobcea, and has generally been known as Coleosporium Senecionis. 



Recorded also in France, Belgium, Netherlands, Germany, Russia, 

 Bohemia, Hungary, Transylvania, Switzerland, Italy, Asiatic Siberia, and 

 North America. 



Sacc. Syll. vii. 2633 ; Ploior. Brit. Ured. p. 249 ; Cook&, Hdbk. No. 1600 ; 

 Cooke, M.F. p. 191, t. ii. f. 27, 28 ; Hart. & Som. Dis. Trees, p. 172, 

 fig. 102 ; Marshall Ward, Timbers &c. p. 256, figs. 37-39. 



Pine Witches' Broom. 

 Peridermium clatinum (A. & S.), PI. XXI. fig. 47. 



This parasite produces on the branches of Pinus Pinea that peculiar 

 form of distortion known as "Witches' Broom. The mycelium causes 

 fusiform swellings in the branches affected, from which arise the deformed 

 shoots, bearing pale green swollen leaves. 



The cups are whitish, opening irregularly. iEcidiospores elliptical or 

 angular, coarsely warted (16-30 x 15-17 /<). 



Known in Germany Belgium, Hungary, and North America. 



Sacc. Syll. vii. 2932 ; Plowr. Brit. Ured. 271 ; Cooke, Hdbk. No. 1601 ; 

 Cooke, M.F. p. 104 ; Hart. & Som. Dis. Trees, p. 179, figs. 109-111. 



Silver Fir Cluster-cups. 

 JEcidium pseudo-cohmmare (Kulin), PI. XXI. fig. 48. 



This is the species which has been known in tliis country as Peri- 

 'hrmium ciiluvi if" r, but which I >r. Plowright affirms is not that species, 

 but another which is known by the above name. It occurs on Abies 

 pectinata, Nordmarmiana, amabiUs, and ccpJuthmica, as well as on 

 Spruce. 



The clu iter cups appear in two rows on the under side of the affected 

 leaves, which arc not otherwise altered, except tlmt they are paler in 

 colour. Tiny are either spherical or elongated, with the edges irregularly 

 torn. JEddiospores white, finely warted, ovate or long elliptical, some- 

 times irregular, angular, and even triangular in Bectii □ <'■>'■'■ B7x 18 25 ft). 



