Parasitic Fungi of Illinois. 399 



On Rosa sps.: Cook, Sept. 7, 1458; McHenry, Aug. 20, 

 1212; Pulaski, May 5, 4537. Rose stems: Champaign, 

 autumn (Burrill). Rosa lucida: Union, Aug. 20 (Earle). 



Winter (Die Pilze, IL, p. 26) and Saccardo (Syl. Fung. I., 

 p. 2) describe this species with hyaline appendages; but Tulasne 

 (Fung. Carp. Select. I., p. 208) describes them as colored. 

 They frequently are colored in our specimens. De Bary 

 (Morph. und Phys. der Pilze, II., p. 48) says "colorless or 

 brown at base." 



S. mors-uvsB, (Schw.) B. & C. 

 (Grev. IV., p. 158.) 

 Erydphe rrurrs-uvss, Schw. (N. A. Fungi, p. 270). 



Mycelium abundant, at first white, becoming dark brown, 

 densely covering the leaves, stems, and, fruit; perithecia most 

 abundant on the stems and fruit, densely aggregated, embedded 

 in the thick, felted mycelium, variable in size, 90-120 (», dark 

 brown, reticulations obscure; appendages short, delicate, 

 hyaline or slightly colored, interwoven with and overrun by 

 the dense mycelium; ascus broadly elliptic, eight-spored, both 

 ascus and spores smaller than in S. pannosa. 



On Ribes rotundifoliiim : McLean, July 16, 2373; La Salle, 

 June 16, 5216. Rihes (cultivated): Pulaski, May 8, 4572; 

 Union, June 22 (Earle). 



This is the common '' gooseberry mildew." It has been 

 referred to S. pannosa (Bessey, Erysiphei, p. 3, etc.), but it is 

 sufficiently distinguished by its dense, dark-colored mycelium, 

 which is strikingly unlike that of most of the Erysiphece. 



S. pruinosa, C. & P. 



(Erysiphei of the U. S.) 



Hypogenous; mycelium thin, effuse, persistent; conceptacles 

 minute, black; appendages few, long, colorless, sporangium, ovate, eight- 

 spored. 



Leaves of Rhus glabra. Greenbush, August. 



The long colorless appendages readily distinguish the species from 

 the preceding \8. Castagnei, L^v.J. The whole surface of the leaf appears 

 pruinose. — Peck, 25th Eep. N. Y. State Mus., p. 94. 



On Rhus copallina: Union, Sept. 17 (Earle). 

 Our specimen is not sufficient for full identification, but it 

 is doubtless the same as that described above by Peck. 



