A FUSARIUM DISEASE OF THE PANSY 



F. A. Wolf 

 (With Plate i8, Containing 4 Figures) 



The pansy, Viola tricolor L., seems to be affected by only a 

 few widely distributed fungi. According to Saccardo's " Sylloge 

 Fungorum," the following fungi are known to occur on the pansy 

 in various parts of the world : Asteroma latehrarum Grogn., 

 France; Catharinia americana (Ell. and Ev.) Sacc, America; 

 Cercospora Violae-tricoloris Br. and Cav., Italy; Oidium Violae 

 Pass., Italy; Peronospora Violae De Bary, Germany, Britain, 

 America; Phyllosticta Violae Desm., Germany, Hungary, Italy, 

 Britain, France; Puccinia Violae (Schum.) DC., Europe, Asia, 

 America; Ramularia agrestis Sacc, Germany, Italy; Ramiilaria 

 lactea (Desm.) Sacc, Germany, Hungary, Italy, France, Britain; 

 Synchitrium aureum Schroet., Europe, America ; Urocystis Violae 

 (Sow.) Fisch., Germany, Britain, Holland, Italy, France; Phoma 

 Violae-tricoloris Diedicke, Germany; Cladochytrium Violae Ber- 

 lese, Italy; Colletotrichum Violae-tricoloris Smith, America. 



Most of these fungi occur on the leaves, several of them being 

 saprophytic or else appearing only on languid or dying leaves. 

 The violet rust, Puccinia Violae, which is parasitic on all of the 

 aerial parts of the plant, is perhaps the most common. The violet 

 smut, Urocystis Violae, appears on the petioles and leaves and 

 has been generally reported from Europe. Colletotrichum Violae- 

 tricoloris causes a spotting of the leaves very similar in appear- 

 ance to the common leaf-spot of the violet and also affects the 

 petals, causing them to die along the margins and often inhibiting 

 their development so that the flowers are malformed. Clado- 

 chytrium Violae, one of the Chytridineae, is parasitic on the 

 roots of pansies in Italy, forming its spores within the tissue of 

 the host. It is only in extreme cases that the entire plant or entire 

 beds are killed by the ravages of any of these forms, although 

 some parts of the plants are often badly affected. 



During the past two years a stem and root disease has been 



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