304 



GENERAL PLANT PATHOLOGY 



Parts of trees, however, may be killed.* The larch mistletoe, Razou- 

 mofskya Douglasii laricis, is one which lives on the western larch in 

 Idaho and Oregon and in the open places interferes seriously with the 

 development of some of the more valuable timber trees. 



The sixth series includes the climbing parasites, which are destitute 



Fig. 121. — Sectional view, partly diagrammatic, of a branch infected with 

 mistletoe, showing relation of parasite and host, u, branch of host tree; b, mistletoe; 

 t. primary sucker; d, sucker from cortical root; e f, cortex; g, cambium; h, wood 

 of branch. (After Bray, W. L., Bull. i66, U.S. Bureau of Plant Industry. Feb. 2, 1910.) 



' The student should consult the following for more detailed information about 

 mistletoe. Sorauer, Dr. Paul: Handbuch der Pflanzenkrankheiten (2d edition, 

 1886, ii: 25-32; Peirce, George J.: The Dissemination and Germination of .ilrccMiAo- 

 litim occidenlalis. Annals of Botany, xix : 99-1 13, January, 1905 ; York, Harlan H. : 

 The Anatomy and some of the Biological Aspects of the American Mistletoe. 

 Bull. Univ. of Texas, Scientific Series 13, March 15, 1909; Meinecke, E. P. : Parasit- 

 ism of Phoradendron juniperinum, Proc. Soc. Amer. Foresters, vii: 35-41, March, 

 1912; Mistletoe Pest in the Southwest, Bull. 166, Bureau of Plant Industry; 

 Weir, James R.: Larch Mistletoe, do. Bull. 317. 



