Ervsiphe 203 



E, polygoni also belongs to the present species, and together with 

 the forms on Mentha , Ljcopus and Scutellaria are peculiar in usu- 

 ally showing on the living host-plant no trace of spores in the 

 asci. These forms, as well as their connection with E. galeopsidis, 



■m 



are discussed further, 



A rather marked form of E, cicJioraceanun occurs on Senecio 

 vulgaris (Margery, Reigate, England, Oct., 1898). Here the my- 

 celium is persistent and covers the stems with a continuous white 

 covering, in which the perithecia are more or less immersed, giv- 

 ing an appearance very similar to that of the forms of E. polygoni 

 on Liriodcndron, Dteridlla, etc. We not unfrequentl}' find, how- 

 ever, E. cichoraecaruvi on other host-plants with a thin effused 

 persistent mycehum on the leaves, as in some American examples 

 on species of HeliantJuts and on Andvosia trifida — sometimes, as 

 in some specimens on Hydi^ophyUnvi Virginicum the mycelium has 

 a decidedly pink color. 



An American form on Bigelovia viseidiflora [B. Douglasii^ 

 (Willis, Montana, Oct., 1888, leg. F. W. Anderson, in Herb. 

 Missouri Bot. Gard.) is remarkable for the often large size of the 

 perithecia, which measure from 100-175 «, and for the numerous 

 asci, which are sometimes as many as 16. In these characters the 

 fungus approaches both E. polygoni \zx, sepulta and j5". tanrica ; 

 from the former it differs in the regularly bisporous asci, from the 

 latter in the slightly smaller perithecia, apparently not becoming 

 conspicuously concave or pezizoid, slightly smaller asci and 



w 



smaller spores. Although this form has been generally referred 



to E. cicJioracearuni by American botanists, it must be considered 

 a marked form of this species in the larger perithecia and more 

 numerous asci (I have not seen elsewhere in E, cichoraeearnm 

 perithecia larger than 140 /i in diameter), and certainly makes the 

 nearest approach of any American Erysiphc to the Old World 

 species E, tanrica. I have seen only the one specimen quoted 

 above, and this, unfortunately, for the most part scarcely mature. 

 In Grevillea, 15: 98. 1887 the following description of an 

 Erysiphc \\2iS given; " £". vitigera Cke. et Mass. Hypophylla, 

 mycelio floccoso, persistente, peritheciis gregariis, minutissimis 

 (4 mm. diame.), sphaeroldeis ; appendicibus obsoletis vel cum 

 mycelio intertextis, ascis poriformibus (4 in singulo perithecio) 



