192 FUNGOID PESTS OF CULTIVATED PLANTS. 



Another species (PhyUosticta syringicola) is known in France with 

 reddisli- brown spots and larger sporules (12-15 x 2 /x). 



Tea-tree Mildew. 

 Microsphara Lycii (Lasch.), PL XVIII. fig. 33. 



This powdery mildew is very common on the leaves of Lycium 

 barbarian, bnt in this country it is rarely seen proceeding beyond the 

 conidial stage, when the leaves are covered with Oidium. The mycelium 

 is persistent, adhering by means of suckers, or haustoria, entirely covering 

 the leaves and twigs with a coating of white. When the receptacles make 

 their appearance they are minute and flattened, globose, with a great 

 number of spreading appendages, twice as long as the diameter of the 

 receptacles, about four times forked at the apex, with the tips obtuse. 

 Each receptacle contains from twelve to sixteen asci, and each ascus only 

 two sporidia. 



It is recorded in France, Germany, Italy, and in North America. 



If necessary, sprinkle with powdered sulphur. 



Sacc. Syll. iii. 33; Cooky, M. F. p. 240. 



Sida Leaf-spot. 

 PhyUosticta sidacola (Cooke). 



Hitherto only this kind of leaf-spot has been observed in this country 

 on leaves of Sida and Hibiscus, and this upon leaves of Sida Nap<ea, 

 forming brown indistinct spots, pallid in the centre. The sporules are 

 minute and elliptical (4 x2/*). 



Grevillea, xiv. p. 39, 72. 



There is another species found on the leaves of Hibiscus syriacus in 

 Portugal and Italy, but we have not heard of it in Britain (PhyUosticta 

 syriaca , The spots are bleached, with a broad tawny margin, and the 

 sporules are almost ellipsoid (7x3-4/;). 



CaLYCANTHUS Le \I'-si'OT. 



Although Calycanthus is not uncommonly cultivated in gardens, it 

 appears hitherto to have escaped the pests which attack it on the 

 Continent. 



PhyUosticta Calycanthi (S. & S.) occurs in Italy and causes variable 

 spots, which become bleached, and bear the usual small perithecia, which 

 contain ellipsoid sporules (7-9 x 5-6 /x). 



Sacc. Syll. iii- 85. 



Aicochyta Calycanthi (S. & S.) also is found in the same country, 

 forming variable bleached spots on the leaves, and producing unisoptato 

 sporules (11 1 1 x2j 8/*). 



Sacc. Sytt. iii. 2165. 



Septoria Calycanthi (S. & B.) is yet another Italian leaf pest which 

 forms ochraceous spots on the leaves of Calycanthus, and evolves 



