98 FUNGOID PESTS OF CULTIVATED PLANTS. 



and Sphceronema Lycopersici. The latter has been renamed Glczosporium 

 phlomoides. Doubtless they will all prove harmless enough for any other 

 purpose than to allow the writer a remote chance of becoming immortal 

 by means of strings of useless names. No fungicides will be required. 



MINT BUST. 

 Puccinia Mentha (Pers.), PI. VIII. fig. 122. 



All kinds of Mints are liable to infection from the common Mint 

 rust which is plentiful on wild Mints : in gardens mostly when in damp 

 situations. 



There is very little indication on the upper surface of the leaves, but 

 the under surface is either sprinkled or closely beset with the roundish 

 pustules, both of the uredospores and teleutospores, usually in company, 

 the latter darker than the former, but both of them equally powdery. 

 The cluster-cups are rare. 



The uredospores are one-celled, roundish, and of a cinnamon-brown, 

 the surface studded with minute spines (17-28 x 14-19 /*). 



The teleutospores are nearly black in the mass, oval, divided across 

 the middle into two cells, with a slight constriction at the suture. The 

 apex of the upper cell is furnished with a small papillary tubercle ; the 

 lower cell is attached to a deciduous stem. The whole surface of the 

 spore is covered with small warts (26-35 x 19-23 /*). 



Possibly should a patch of Mint become diseased, it would be well to 

 try cutting it down to the ground and burn it, since it may prove that 

 the- disease has not extended to the roots, and the new growths may be 

 free, especially if cut down before the teleutospores have matured and 

 fallen to the ground. 



Common nearly throughout Europe, and in South Africa and North 

 America. 



Sacc. Syll. vii. 2180 ; Mass. PL Dis. 240 ; Cookc, M. F. p. 204, 

 figs. 69, 70 ; Cooke, Hdbk. No. 1474 ; Plowr. Brit. Ured. 157. 



BHUBAEB CLUSTER-CUPS. 

 Mci&ium rubellum (DC.). 



Ehubarb leaves in gardens are sometimes disfigured by the large 

 patches of this parasite, although by no means commonly so. The same 

 fungus is common on the leaves of various species of Dock, from which 

 it may extend to Rhubarb. 



It is very handsome, as far as appearance goes, and forms large crim- 

 son spots, nearly an inch in circumference, while in the centre of these 

 spots the cluster-cups are crowded and densely packed together. The 

 white edges of the cup are torn like a fringe, and the secidiospores, which 

 occupy the centre of the cup, are produced in chains in the interior, and 

 are nearly globose and rough. 



No further development has been seen upon the Rhubarb leaves, 

 since it is affirmed that both the Uredo and Puccinia are developed upon 

 another and quite a different species of plant, which in reality is one of 

 the Grasses. But our disease now concerns only the Rhubarb leaves. 



