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MANUAL OF TREE DISEASES 



Limb-Gall 



Caused by Bacterium tumefadens E. P. Smith and Townsend 



Poplar is only one of the many kinds of woody and her- 

 baceous plants affected by this gall. The disease occurs 

 commonly on fruit-trees, roses, daisies, beets and many other 

 kinds of cultivated and wild plants. The over-growth in the 







Fig. 57. — Limb-galls on poplar. 



affected plant-tissue assumes different characters and the 

 disease is variously known as: crown-gall, limb-gall, crown- 

 knot, root-gall, hairy-root and woolly-knot. In general it is 

 called the plant-cancer. Many trees are commonly found with 



