PERENNIAL MYCELIUM OF PARASITIC FUNGI 261 



simut of quack grass and the wild rye smut may prove very dis- 

 tinct species. Experiments can only determine whether the 

 infection occurs at blossoming time or whether the -seed becomes 

 infects! . 



We have a laro'e number of fungi wliich are perennial. For a 

 number of j-ears the writer has ol)served the sycamore blight 

 Fungus (Gnammiia veneta (Sacc & Speg) Kleb) on a single tree 

 on the college farm. The mycelium is perennial in the buds. 

 This fungus produces the well known hexenbesen. Early in the 

 season, this year, there was not a single sound leaf on the tree, 

 the young leaves were all blighted with the (iloeosporium stage 

 of the fungus. Later, however, new leaves appeared. In some 

 seasoas the fungus is much more abundant than others. The 

 writer has, however, never failed to see some of the fungus. 

 Later in the season many of the leaves may be merely spotted. 

 Duggar^" states: "Upon Sycamore it is in one stage primarily 

 a disease of the leaf veins, although conunonly the death of con- 

 sideral>le portions of the lamina adjacent soon follows. In an- 

 other stage the fungus is notably fatal to shoo's, young trees and 

 seedlings. Edgerton^^ has noted that this fungus may produce 

 in the early spring an effect similar to frost injury." J. P. 

 Anderson^- made the same oljservations on sycamore blight in 

 Ames and E. A. Southworth" mentions the same kind of spots 

 and diseased twigs from Washington, D. C. F. Lamson- 

 Scribner** also describes the sudden waiting of the twigs due 

 to the fungus from Washington, D. C, where he studied it. 



During the season of 1916 there was a great deal of buckeye 

 blight {Phjjllosticta pavtae Desm) on the Ohio buckeye 

 (Aescidus glabra var. actandra). During the next season (1917) 

 the same groves were visited in July. The trees looked unusu- 

 ally healthy. Not a single diseased leaf could be found. The 

 evidence indicates that the fungus is not perennial. Infection 

 depends on the time and character of the weather. 



The white oak blight {Gloeosporiu-ni sp.) was almndant during 

 the season of 1915 in many parts of Iowa. In some places the 

 trees looked as though they had been sprayed with an arsenical 

 spray. There was comparatively little in 1916, but in 1917 

 there was a great deal in some trees. It does not seem as if the 



-'Pungius Diseases of Plants, 180. 

 ^'Bot. Gazette, Jio, 367-408, vl. 11. f. 1~. 



■^Proc. Iowa Acad, lof Science, 21, 109. 

 '=Jour. Mycl., -7, 51-52. 

 '*Rep. V. S. Dept. A^rl., 1888: 388. 



