288 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Shot-hole Fungi. 



Certain fungi are commonly known as " shot-hole fungi " on account of 

 the leaves which have been attacked by them having the appearance of 

 having been riddled by a charge of shot. The holes caused by these fungi 

 when they become larger (sometimes one or more becoming confluent) 

 very much resemble those made by certain insects when feeding on the 

 leaves, and it is difficult sometimes to decide whether the injury has been 

 caused by a fungus or an insect. In this connection the following letter 

 was received from one correspondent : — 



" We have a large plant of Bomneya Coulteri which I got about four 

 years ago. 



The second year here it flowered grandly. 

 " The third year it had some flowers, but was eaten to pieces by 

 something. 



" This year it bore only two flowers, and was terribly eaten all over. 

 We have a good and careful gardener, but both he and I are puzzled, as 

 we have watched and searched in vain, only catching a few earwigs and 

 three or four green caterpillars. 



" We have tried liming the ground and syringing the bush, but nothing 

 seams of any use. I am sending you a few of the branches in case you 

 can kindly help us." 



The reply given to this letter was as follows : — 



" The Bomneya is attacked by one of the shot-hole funguses, 

 Gladosporium elegans. The bits of leaf that drop out carry the fungus 

 fruit whicli produces infection next year ; hence the surface soil should 

 be removed during the winter and fresh soil added. Spraying with 

 sulphide of potassium — one ounce to three gallons of water — will check 

 the spread of the fungus on the living leaves." 



Black Cuerant Rust. 

 Cronartium rlblcohtni . 



This rust was first brought to my notice as a British species from 

 Haslemere, September 21, 1906, although known on the Continent for some 

 generations. It occurs on the under surface of black currant leaves, where 

 the uredospores are found in crowded pustules of an orange rufous colour. 

 The spores are elliptical, oval or ovoid 19-35 x 14-22 with a hyaline 

 coat, and orange contents. At length a slender columella issues from the 

 centre of each pustule to about 2 mm. high, which is curved, yellowish, 

 and horn-like, composed of one-celled teleutospores. These often germinate 

 at once, bearing two or three secondary spores near the end of the germ 

 tube. 



This is now regarded by many as a heteroecious uredine, with its 

 oecidium stage on living bark of the Weymouth pine, this condition being 

 known as Peridermium strohi. 



It is advisable to collect and burn all currant leaves attacked by the 

 parasite and syringe all the bushes with Bordeaux mixture. This may 

 minimise future attacks, but it is doubtful whether it wiU make the bushes 

 recover.— M. C. C. 



