54 MANUAL OF TREE DISEASES 



of slimy mal-odorous ooze. Certain species of fungi closely 

 related to the yeasts are commonly found in this ooze, along 

 with other fungi and bacteria. Fermentation of the sap which 

 is exuded from the fresh wound causes the death of the bark 

 and wood adjacent to the wounded tissue and often large areas 

 of bark are killed. It is not known what specific action the 

 different organisms in the slime exercise in causing the death 

 of the bark. It is supposed that they do not act as parasites 

 but rather that the products of fermentation slowly produce the 

 death of the adjoining tissues. 



The most important step in preventing slime-flux is to care 

 for any wounds before the ooze begins to form. Trees which 

 bleed commonly should be watched so that any wounds that 

 occur can be shaped and immediately prepared for rapid 

 healing. If bleeding continues and a wound-dressing will not 

 adhere, the surface of the wound may be cauterized with a 

 gasoline torch. Old wounds which have developed slime- 

 flux should be cleaned and treated in the same way. For 

 directions regarding tree surgery methods, see page 345. 



Mistletoe Diseases 

 Caused by species of Razoumof skya (Arceuthobium) and Phoradendron 



Several species of parasitic flowering plants, belonging to 

 the family Loranthacese, cause considerable damage to trees. 

 The composite species Phoradendron flavescens, the American 

 mistletoe, grows on many kinds of deciduous trees and shrubs 

 in southern United States, while numerous species of the genus 

 Razoumofskya (the dwarf mistletoes) grow on conifers, causing 

 much damage in the forest, especially west of the Rocky Moun- 

 tains.^ In Europe members of the mistletoe family are impor- 

 tant tree parasites. 



' The generic name Arceuthobium is retained as one of the nomina conservanda 

 of the International Rules for Botanical Nomenclature. Under the American 

 Code, the name Razoumofskya is revived. 



