PAPERS ON BOTANY 127 



mushroom. It is considered rare, but it has occurred very 

 abundantly in several localities north of Urbana during the 

 past two seasons. t 



The plant was first described by Peck in 1884 as Panaeolus 

 epimyces/ It was redescribed by Atkinson in 1902 a , 

 and again in 1907,* and placed in the genus Stropharia be- 

 cause of the purplish tinge of the spores and the presence of a 

 ring on the stem. Both of these characters are evident in 

 the specimens collected about Urbana and these specimens 

 seem to be nearer to the genus Stropharia than to Panaeolus, 

 although the ring is very slight and is near the base of the 

 stem. It is the same type of ring as that which is formed 

 in the common inky cap mushroom, Coprinus atramentarius. 

 A study of the development of the fruit body, such as I hope 

 to be able to make from material which I now have, will un- 

 doubtedly throw considerable light upon the relationships of 

 the plant. 



S. epimyces occurs either singly or in clusters. Figure 6 

 shows an extra large cluster. The plant grows from 3 to 8 

 cm. high and the cap is from 2 to 6 cm. broad. The cap is 

 dingy white in color and somewhat floccose scaly. The gills 

 are attached to the stem and are dark brown. The spores are 

 nearly black but have a slight purplish tinge. No one would 

 fail to recognize this mushroom after once seeing a picture 

 of it. 



The identification of the host plant was first published by 

 Atkinson in 1902," as Coprinus atramentarius. In 1905 a 

 second host, Coprinus comatus, was added by Miss Sherman,' 

 All specimens collected at Urbana have been on the shaggy 

 mane mushroom, Coprinus comatus. Fig. 7 shows an interest- 

 ing series. At the left is an unparasitized specimen of Coprinus 

 comatus. Next to it is a pair of specimens deformed by the 

 parasite which is present but has not developed fruit bodies. 

 The third specimen has two partly developed fruit bodies of 

 the parasite on it, and finally there is shown the fully matured 

 parasite on a host so badly deformed as to be scarcely recogniz- 

 able. 



^cDougall, W. B., Am. Journ. Bot. 1:51, 1914. 

 a 35th Rept. N. Y. State Mus. Nat. Hist. 133, 1884. 

 3 Jour. Myc. 8:118, 1902. 

 ♦Plant World, 10:121, 1907. 

 "Tour. Mycol. 8:118, 1902. 

 •jour. Mycol. 11:167, 190S. 



