Parasitic Fungi of Illinois. 401 



ages long, stout, usually colored throughout, fiexuous, some- 

 what uneven in width, more or less interwoven with the my- 

 celium; ascus rather small, elliptical or suborbicular; spores 

 usually 8, small, about 15 ,1* long. 



On Bidens frondosa: Jo Daviess, Sept 15, 5904; Stephen- 

 son, Sept. 13, 5842; Lee, Sept. 9, 5743; McLean, July 2, 2370; 

 La Salle, Sept. 12, 1489, Sept. 16, 1554; Henry, Sept. 28, 1708; 

 McHenry, Aug. 20, 1168; Union, Sept. 13 (Earle). Bidens 

 connatus: Rock Island, Sept. 24, 1624; Fulton, Oct. 1, 1777. 

 Erechthites hieracifolia : McHenry, Aug. 23, 1234; Champaign, 

 Sept. 19, 6615; Adams, Aug. 20 (Seymour). Nabalus sps.: 

 McLean, Sept. 20, 5662; Jo Daviess, Sept. 16, 5945. Taraxi- 

 cum dens leonis: Champaign, Oct. 16, 6580, Oct. 23, 6590. 

 Veronica Virginica: McHenry, Aug. 27, 1333; Stephenson, 

 Sept. 13, 5809, Sept. 14, 5878; Jo Daviess, Sept. 15, 5906. Sept. 

 18, 5975, Sept. 19, 6002, Sept. 20, 6017; Ogle, Sept. 23, 6134. 

 Gerardia grandiflora: Ogle, Sept. 23, 6129. Brunella vulgaris : 

 McLean, July 3 (Seymour); Champaign, Oct. (Waite). 



This abundant and widespread species can be easily distin- 

 guished from the form on Bosacece, etc., that has usually 

 been associated with it, by the peculiarly low and large- 

 celled, wall of the perithecium, and by the larger, more fiexu- 

 ous appendages. The spores, too, average smaller. It varies 

 considerably on the different hosts, in the appearance of the 

 mycelium and the size of the perithecia, these being larger 

 than the average on Erechthites and usually smaller on Veroni- 

 ca; but the more important characteristics appear to be con- 

 stant. 



Erysiphb, (Hedw.) Ltv. 



(Ji.nn. Sci. Nat., Ser. III., Tome. XV.j 



Perithecium containing several 'asci; appendages simple 

 threads similar to and frequently interwoven with the my- 

 celium. 



E. liriodendri, Schw. 



(N. A. Fungi, p. 269.) 



On leaves and succulent stems. Mycelium abundant, dense, 

 white, persistent; perithecia developing late, mostly after the 



