ASCOMYCETES 



193 



the surface of the mummied fruits. The fruits upon which this 

 stage appeared had been lightly covered with sandy soil for at 

 least a year. In 1906 this stage was extremely common through- 

 out the West. Conditions seemed to be most favorable for its de- 

 velopment where the fruit had lain for eighteen months in little 

 depressions in the sod, and fairly well covered by grass debris. 

 The stalk or stipe of the apothecium was from .5 to 3 cm. in 

 length, depending upon the distance of the mummy beneath the 

 soil. The stipe is dark brown and the slightly bell-shaped disk 

 is a shade lighter. The latter is usually 5-8 mm. in diameter, 

 though it may range from 2 to 1 5 mm. The general appearance 



Fig. 73. Apothecia of Sclerotinia from Mummied Plums 



of the apothecia is shown in Fig. 73. The stipe consists of a 

 medulla of elongated, intertwined, brown cells and a cortex of 

 shorter, darker ones, the latter being continued in a tissue pro- 

 jecting beyond the hymenium. The asci are cylindrical-clavate, 

 125-215 x 7-10 /jl. 1 They arise from a dense layer of small 

 hypha?, differing from the general medullary hyphse merely in be- 

 ing more closely intertwined (Fig. 72, c and d). The ascospores 

 are ellipsoidal and measure 10-15 X 5-8/*. They are obliquely 

 uniseriate, or subseriate. The paraphyses are characteristic of 

 many Pezizaceae, — hyaline, septate, simple or branched, filiform, 

 and slightly swollen at the tips. 



1 Reade, J. M. Preliminary Notes on Some Species of Sclerotinia. Annales 

 Mycologici 6 : 109-116. 1908. 



