FUNGOID PESTS OF CULTIVATED PLANTS. 



171 



species of Protomyces, and as the observations have not since been 

 confirmed whether it is the true cause of spotting. 

 Gard, Chron. Sept. 23, 1882, fig. 63. 



OECHID BUST. 

 Uredo Lynchii (Berk.), PL XV. fig. 28. 



Our indigenous Orchids have long been known to be subject to the 

 attacks of a bright orange Uredo, which is not at all uncommon, but 

 there is no record of its having attacked Orchids under cultivation. For 

 this purpose another and similar rust has made its appearance, and the 

 golden rust which from time to time is found on the leaves of more than 



u 



FIG. 23. PROTOMYCES CONCOMITANS. (Gardeners' Chronicle.) 



one species of Spiranthes claims to be quite a different rust from that of 

 wild Orchids. 



The spots are small and scattered, but not numerous, sometimes not 

 more than half a dozen pustules on a leaf. The uredospores are yellow 

 andobovate, covered with minute spines (28-35 x 20-30 /a) and produced 

 on short footstalks. It has made its appearance, more or less, every year 

 in Orchid-houses, and as soon as it appears the leaf should be cut off and 

 burnt. By such measures it has hitherto been kept in check where it has 

 appeared. 



Sacc. Syll. vii. 3069 ; Gard. Chron. Aug. 25, 1877 ; Grevillea, vi. 126 ; 

 Plowr. Brit. Ured. 259. 



ORCHID LEAF-SPOT, 

 Leptothyrium perniciosum (Berk.). 



In the year 1865 Berkeley described a kind of spot on Orchids and 

 the fungus producing it, with the above name, and this we are obliged to 



