CLITOCYBE ROOT ROT OF WOODY PLANTS 3 



observed it fruiting in great profusion from the roots of dead trees, 

 stumps, and living trees in an area of forest, dominantly oak, a few 

 miles from Neosho in the Ozark section. He also found it fruiting 

 on the roots of a declining silver maple (Acer saccharinum) street 

 tree at Neosho. 



Walker (32) and Hewitt and Hay hurst (10, p. 4^4) reported that 

 root rot of fruit trees was widespread in Arkansas and caused serious 

 damage in some localities. Walker (32) stated that "besides the 

 apple, it affects probably all the commonly cultivated fruit trees, the 

 grape, as well as a number of forest trees," and that the disease is 

 caused by toadstool fungi, two forms concerned being Glitocybe para- 

 sitica and Armillaria mellea. A much later report (1, p, 48) from that 

 State mentioned that both these fungi had been under observation for a 

 number of years and had been found commonly parasitizing several 

 types of plants, including privet hedges and apple and peach trees, as 

 well as grapevines. 



Stevens and Hall (29) reported the death of trees in apple orchards 

 in Hayward County, N. C, and stated that "investigation showed 

 the presence of a fungus, which, to all appearances, was Glitocybe 

 parasitica" Fromme (9), in a report on the black root rot disease of 

 apple, caused by Xylaria mali, stated that "the symptoms allow this 

 disease to be easily distinguished from the so-called white root rot 

 (believed to be caused by Glitocybe wfbonadelpha) which occurs in 

 some parts of Virginia occasionally, causing an appreciable loss of 

 apple trees." It has been suggested by Dr. J. S. Cooley, of the United 

 States Department of Agriculture, that Glitocybe possibly was blamed 

 for some root rots of fruit trees that may have been due to Gorticium 

 galactinum before this fungus was adequately described. He consid- 

 ers this particularly true in the northern limits of Glitocybe, as in 

 Virginia. 



Authentic records of the occurrence of Glitocybe root rot in Florida 

 have been found by the writer to date back to 1902, when it was 

 recorded by Dr. H. Harold Hume, of the Florida Agricultural Experi- 

 ment Station, on peach and other trees at Lake City, and records of 

 the sudden dying of guava trees from what undoubtedly was this dis- 

 ease have been found dating back to 1885. It was reported by Hole 

 (12) in 1905, as troublesome in peach orchards on newly cleared ham- 

 mock land at Fulton, east of Jacksonville, near the mouth of the St. 

 Johns Kiver. Fawcett (8, p. 66), in 1911, mentioned this as one 

 of the peach diseases being studied by O. F. Burger. The destructive- 

 ness of this disease in a commercial peach planting on newly cleared 

 pine-oak land near Blanton, Fla., was reported by the writer (21) 

 and also by Thornton (30) in 1940. According to the estimate of the 

 latter, root rot had attacked 38 percent of the 1,400 trees by the time 

 they had attained an age of 3% years and had killed 192 trees. 



In the earlier records of Clitocybe root rot the disease attracted at- 

 tention chiefly as an important cause of loss in orchard trees and, later, 

 grapevines. Even in subsequent years, with the exception of Florida, 

 only the most meager observations have been made in regard to its 

 occurrence on forest, shade, and ornamental trees and shrubs. Ex- 

 tensive studies of this disease have been conducted by the writer in 

 Florida over a period of 20 years. Some results were published in 

 the Florida Agricultural Experiment Station Annual Reports and in 



