PESTS OF THE ORNAMENTAL SHRUBBERY. 



19 



flesh colour. The conidia spindle-shaped, straight (16-20 x 3-4 ^u), sup- 

 ported on very short pedicels or spore-bearers. 



Although this is a kind of mould which is apt to be troublesome, 

 we have not heard of it lately ; should it appear, the effect of spraying 

 with Bordeaux mixture should be tried. 



Grevillea, xvi. 18, 58. 



A kind of leaf-spot is known on Deutzia scabra in France (Septoria 

 phyllostictoides), which may find its way into this country. 



Mezereum Anthracnose. 

 Glceosporium mezerei (C. & M.), PI. XVIII. fig. 35. 



This species was not recognised until 1890, when it was found to 

 produce small brown pustules on the upper surface of the leaves, without 

 definite spots, but mostly upon fading leaves, probably induced by the 

 presence of the parasite. 



The sporules are somewhat elliptical or almond-shaped, with one or 

 two guttules, and colourless, produced at the apex of short pedicels 

 (15 x 6 fi). 



Sacc. Syll. x. 6768 ; Grevillea, xix. 8. 



The above can scarcely be the same species as the French anthracnose 

 (Marsonia daphnes), which has been found upon greenish and afterwards 

 brownish spots, and has ovoid curved sporules (20 x 4-5 /»), acute at each 

 end, and divided into two unequal cells. This has been recorded for 

 France and the Netherlands. 



Hawthorn Leaf- spot. 

 Phlceospora oxyacanthce (Kze.), PI. XVITI. fig. 36. 



This common leaf-spot has been known to occur on Hawthorn for 

 many years. The spots are mostly yellowish, or scarcely distinct, the 

 receptacles are seated on the upper surface, from which the mature 

 sporules are extruded in yellowish tendrils. Sporules rod-like, a little 

 thickened downwards (70-80 x 6-8 /x), at first with granular contents, 

 afterwards divided by from six to eight transverse septa. 



Known in Sweden, Germany, Austria, Portugal, and Italy. 



Sacc. Syll. iii. 3139 ; Cooke, Hdbk. No. 1299. 



Hawthorn Powdery Mildew. 

 Podosphara oxyacanthce (DC), PI. XVIII. fig. 37. 



It is by no means uncommon to see the leaves of Hawthorn whitened 

 with this mildew, which sometimes does not pass beyond the Oidium 

 stage, and the leaves are powdered with the fallen conidia. When the 

 receptacles appear they are minute, globose, and scattered over the 

 mycelium. The appendages which surround the receptacles are from 

 eight to ten, and about equal in length to the diameter of the receptacles. 

 They are shortly branched at the apex, with the tips of the branchlets 



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