6o British Uredinecs and Ustilas^inecE. 



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Uredineae. These permeating mycelia, whether of the 

 Uredineae or Ustilagineai, are perennial. When the plant, 

 if perennial, dies down in winter, the mycelium, of course, 

 dies down with it, but remains alive, although quiescent, 

 in the upper part of the root-stock ; and when fresh shoots 

 are sent up in spring, the mycelium is sent up in them. 

 One peculiarity of most of the Ustilagineous mycelia is 

 that, although it pervades more or less the whole plant, 

 it produces its spore-formation at certain favoured places 

 only ; these are, for the most part, in the flowers or seeds 

 of the plants, but not always, sometimes on the stems or 

 in the leaves. The place of spore-formation, however, is 

 constant with each species. If a plant affected with one 

 of the Ustilagineae be transplanted into a garden, it will, 

 year after year, be affected with the parasite. In my own 

 garden at King's Lynn I have had growing for the past 

 six years, plants of Colchicum aiitmmiak affected with 

 Urocystis colcJdci, Tritiaim repens with U. hypodytes, and 

 Avena elatior with U. segehim. De Bary mentions that 

 a plant of Saponaria officinalis, in the Freiburg Botanic 

 Garden, was for more than ten successive years affected 

 with U. violacea. 



