Fig. 3. — Lower surface of Douglas -fir needles covered with mature apothecia of 

 the fungus R. pseudotsugae. June 1957. (X 7) 



MATURATION OF APOTHECIA 



In central New York maturation of the apothecia occurred 

 between May 15 and June 1 in 1956 and 1957. In 1956, in the Cam- 

 den plantation, mature fructifications developed more than a week 

 in advance of those in the Cortland plantations. At apothecial 

 maturity the epidermis, lifted by the growth of the hymenium 

 (Fig. 3), is split lengthwise or raised at the end to partially or com- 

 pletely expose the orange-brown hymenium. In the cool, wet spring 

 of 1956, apothecia in this stage of development were first found 

 May 15 at Camden, and May 21 at Cortland. During the extremely 

 dr) April and early May of 1957, one-year-old needles of Douglas-fir 

 infected with R. pseudotsugae were fully browned and appealed too 

 dry to persist on the trees. Light but steady rains began May 10, and 

 by May 13 many apothecia were open. In both years apothecia con- 

 tinued to mature and open throughout June and most of July. 



Bud opening in 1956 and 1957 was highly variable, depending 

 apparently upon the individual tree and the exposure of the tree. 



23 



