PESTS OF THE ORNAMENTAL SHRUBBERY. 



21 



The spots are whitish, and at one time or other circled with red. Pustules 

 minute, seated on the spots. Sporules small, elliptical. 



This is another of the species which appears to have been hurriedly 

 described from a single set of specimens, and has not been seen again. 



Berk. & Br. Ann. N. H. No. 1897 ; Grevillea, x. 1881, p. 49 ; Sacc. 

 Syll, iii. 3686. 



Parasites do not appear hitherto to have caused much trouble with 

 Colutea arborescens, notwithstanding its extensive cultivation, so that we 

 have no record of any British species. 



Mountain Ash Cluster-cups. 

 Bcestelia cornuta (Gmel.), PI. XVIII. fig. 40. 



Under the name of Gymnosporangium jioniperinum, the presumed 

 teleutospores which succeed these cluster-cups on twigs of Juniper, the 

 original name is concealed. Our parasite, or at any rate that part of it 

 which concerns us, makes its appearance on the leaves of the Mountain 

 Ash and Amelanchier. They are seated in tufts upon yellow spots, on 

 the upper surface. The cups are long horn-like tubes (up to 8 mm. long), 

 which are curved, and whitish at first, then yellowish or reddish, with a 

 toothed margin. The lecidiospores are spherical, then compressed and 

 angular, of a brownish-yellow colour (20-28 x 16-24 fi), delicately warted 

 on the surface. 



The pest is known in Britain, Belgium, Germany, Finland, Switzerland, 

 Italy, Austria, and North America. 



Sacc. Syll vii. 2607 ; Cooke, M. F. f. 18, 19 ; Cooke, Hdbk. No. 1598, 

 f. 218 ; Sow. Fun. t. 319. 



Sumach Leaf-spots. 



Leaf-spots are numerous, and common, on various species of Bhus in 

 North America, bat we have no record of their occurrence in Britain. 

 There are not less than fifteen species of leaf parasites that are known and 

 described, but probably not five of them are European. 



GYMNOSPERMS. 

 Savin Jelly-rust. 

 Gymnosporangium sabince (Dicks), PI. XVIII. fig. 41. 



According to theory, the proper cluster-cups of this pest are produced 

 upon the leaves, twigs, and fruits of the Pear tree, and it was formerly known 

 as Bcestelia cancellata. The teleutospores are exuded in a gelatinous 

 mass from the branches of Juniper as Sabina. We deal with the cluster- 

 cups as a disease of the Pear tree. 



The teleutospores cause gouty swellings in the branches of the host- 

 plant, and at length break through in irregular conical or cylindrical, 

 obtuse, gelatinous, orange-coloured masses, sometimes compressed, and 

 sometimes divided (10 mm. long) like little flabby tongues. This gela- 

 tinous mass consists of teleutospores with their stems adhering together. 



