224 FUNGOID PESTS OF CULTIVATED PLANTS. 



PINE CLUSTER-CUPS. 

 Peridermium 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 secidiospores are spherical or angular by compression, of an orange 

 colour, and coarsely and thickly warted (30-40 x 18-30 ^). 



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

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

 Jacobcea, and has generally been known as Coleosporium Senecionis. 



Kecorded also in France, Belgium, Netherlands, Germany, Kussia, 

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

 North America. 



Sacc. Syll. vii. 2633 ; Plowr. Brit. Ured. p. 249 ; Cooke, 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 elatinum (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, ^cidiospores 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. 

 ^Ecidium pseudo-columnare (Kuhn), PI. XXI. fig. 48. 



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

 dermium columnar e, but which Dr. Plowright affirms is not that species, 

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

 pectinata, Nordmanniana, amabilis, and cephalonica, as well as on 

 Spruce. 



The cluster-cups appear in two rows on the under side of the affected 

 leaves, which are not otherwise altered, except that they are paler in 

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

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

 times irregular, angular, and even triangular in section (33-37 x 18-25 jj.). 



