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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Witches' Broom of Cherry. 

 Exoascus cerasi (Fckl.). 



Tho.se peculiar malformations, which are known under the name of 

 witches' brooms, are not uncommon on various trees, and amongst them 

 the Cherry. Under these attacks the disease shows itself in the produc- 

 tion of dense tufts of branches, growing apparently from a central point, 

 and forming a bunch like a besom, which is very common on the Birch. 



This malformation is caused by the presence of a fungus similar to 

 that which causes the leaf curl of the Peach, and which appears as a 

 hoary bloom on the branches. The vesicles, or asci, which contain the 

 Bporidia are slender and club-shaped (30-50 x 7-10 enclosing the 

 nearly globose Bporidia (6 9 x 5-7//). These asci are supported at the 

 base upon a distinct stem-cell (10-16 x 5-8 or 3-5 which is divided 

 off from the ascus by a transverse septum. 



Known also in Germany, where it was first recognised and described. 



The only known remedy is to cut out the tufts and burn them. 



Sacc. Syll. x. 1734 ; Tubeuf, Dis. p. 163, figs. ; Mass. PI. Dis. 89, 358. 



Cherry-leaf Scorch. 

 Gnomonia erythrostovia (Awd.), PI. XI. fig. 19. 



This disease sometimes makes it appearance in Cherry orchards in 

 great numbers and proves destructive to the crop. 



The leaves are attacked and soon present a scorched appearance, 

 withering, but hanging on the tree through the winter. Long slender 

 colourless curved conidia are produced, and in this condition it is known 

 as Septoria iKillcns. 



During the winter another and final stage is attained by the fungus 

 produced on the dead hanging leaves (Gnomonia crythrostoma). In this 

 condition the receptacles are immersed in the substance of the leaf, with 

 a short beak, or ostiolum, which pierces the surface. Within the receptacle 

 cylindrical cells, or asci, are produced, each of which contains eight 

 elliptical sporidia, which are colourless and divided by a central septum 

 into two cells (18 x 5-6//), each cell enclosing two guttules, and terminated 

 by B curved hair-like appendage, which soon falls away. (Fig. 6.) 



Known in Germany, Switzerland, and Italy. 



All the dead hanging leaves should be collected and burnt. Frank 

 says that in one district in Prussia this method was carried out for two 

 seasons, after which the Cherry crop, which had been ruined, was 

 restored. 



8aee.Syll. iii. 2037, i. 2214; Mass. PL Dis. V . in. fig. 19; Journ. 

 P. II. 8. xxv. 1901, p. 818, fig. 162, xxvii. p. 1110; Tubeuf, Dis. 222. 



Shot-hole Fungus. 



Several Bpeciea of leaf-spot have been recorded in Australia, and else- 

 where, attacking leaves of Plum and Cherry, forming round spots, the 

 d( ad tissue of wbicli loon falls out and loaves a round hole in the leaf. 



