ON ROSES. 133 



of the last-named, which are very persistent, that the parasite 

 is reproduced again the next season, for it is one of those fungi 

 which have both a summer and a winter stage. Mildew appears 

 in late spring, or it may be not until summer, and as soon as 

 the spores are ripened, they are distributed by various agencies, 

 and a very large area may be involved. If, however, timely 

 application of sulphide of potassium, as named below, is 

 made, the parasite's progress is checked, and there is no winter 

 stage. The leaves of affected trees should all be collected and 

 burnt, as should also the fruits and prunings. 



The chief characteristic of Actinonema roses is the formation 

 of unsightly brown blotches, usually of irregular shape, on the 

 upper surfaces of the leaves, chiefly in the vicinity of the 

 midrib, but by no means confined thereto. The young shoots 

 are also involved, and become blackened and die back. If 

 neglected, the whole of the foliage assumes a yellow colour 

 and quickly falls. A tree thus defoliated, and with the young 

 wood blasted, presents a most deplorable appearance. Though 

 the spots above alluded to 'vary somewhat in shape with the 

 position in which they are found, some being nearly circular 

 in shape, the colour is sufficiently distinct for the fungus to be 

 readily distinguished. 



Orange Rust appears to be much more prevalent than formerly, 

 and certain varieties of the Rose are more liable to attack than 

 are others. The smooth-leaved kinds enjoy the greatest immunity 

 among Hybrid Perpetuals ; but the Teas, Noisettes, and the 

 charming Bourbon Roses, like Souvenir de la Malmaison, are 

 freer still. Stems and leaves are both attacked by Orange 

 Rust fungus, which is characterised by lemon-yellow spots, 

 varying in size with the season. Towards summer, however, the 

 colour changes to a brick-red, and ultimately in autumn to 

 black. 



In all three cases spraying early in the season with sulphide 

 of potassium (|oz. to the gallon of water), will be beneficial, and 

 especially if all leaves, shoots, and fruits are burned. Powdered 

 sulphur, if shaken on when the leaves are damp in the morning, 

 will also be - of assistance. Mildew will not put in an appear- 

 ance if the plants are sprayed with the well-known Bordeaux 

 Mixture when the growths are a few inches long, and again 

 before the buds expand. The Bordeaux Mixture is not a 

 cure for fungoid attacks, but is a splendid preventive if applied 

 before any mildew appears. Actinonema rosce, especially, should 



