R. pseudotsugae was first discovered in Pennsylvania in 1952, 

 and reported by Stambaugh (55) and Stambaugh and Bramble (56). 

 The latter paper reports germination of the ascospores within the 

 apothecia and the apparent relationship between the presence of 

 mature spores and bud opening in the spring. 



Murray (39) reported variations in growth and susceptibility to 

 R. pseudotsugae for different varieties of Douglas-fir planted in 

 Van Vloten's private estate in Holland. The green forms of the host 

 averaged over 20 feet in height and remained healthy, whereas both 

 the blue and grey forms were infected, the former averaging about 

 7 feet and the latter 2 feet in height. According to the author, many 

 of the grey Douglas-fir were killed by R. pseudotsugae. 



Meyer (36) in 1954 studied the degree of susceptibility to needle 

 cast by Douglas-fir in Germany on trees of different origins from 

 the Pacific Northwest. He found the green forms, from Washington, 

 Oregon, and British Columbia, to be resistant, the blue forms (all 

 from Colorado) to be susceptible, and the grey forms to vary con- 

 siderably in susceptibility according to their origin. 



In a study of the disease in Montana, Weistaner (68) in 1955 

 reported the presence of both imperfect stages, Rhabdogloeum 

 pseudotsugae and R. hypophyllum on needles prior to the formation 

 of Rhabdocline pseudotsugae. The exact relationship of these two 

 fungi to R. pseudotsugae was not conclusively determined. 



Subsequent reference to R. pseudotsugae in the literature relates 

 directly, either to further outbreaks of the disease in countries 

 already noted here, or to the establishment of quarantines for pre- 

 venting importation of Douglas-fir growing stock. Such reports have 

 no great bearing on the history of the disease and are omitted. 



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