Parasitic Fanr/i of Illinois. 231 



On Eupatoriuni. Hy])opliyllons. Spots distinct, usually 

 few, conspicuous, yellow; a?eidia irregularly clustered or some- 

 what circinate, short, irregularly split and moderately recurved, 

 soon pulverulent; spores subglobose, epispore rather thin, mi- 

 nutely tuberculate, 18-20 ji*; spermagonia several, scattered, 

 above, honey-yellow. On Enpatoriiim ppifoliafiim: McLean, 

 July'll, 2424. 



On Silphiiiiii : Hypo])hyllous, and often also epiphyllous. 

 Spots distinct, usually w^idely scattered, not large, yellow, 

 a^cidia irregularly associated, scarcely crowded, deeply im- 

 jnersed, and but slightly projecting above the raised epidermal 

 border, margin many times split or pulverulent, little excurved; 

 spores subglobose, often angular, 11-15 fi; spermagonia rather 

 few, conspicuous, reddish brown, central, on both sides of leaf. 

 On Silphiuni inter/ I'ifoliu hi : McLean, May 3, 4852. aS. terebin- 

 th inaceu hi : McLean,lMay 30,4825, June 23, 5274, July 2, 2420, 

 July^ll, 2421. S. laciniatiim: McLean, June, coll. C. A. Hart. 



On Ambrosia: Hypophyllous. Spots large, often conflu- 

 ent, scarcely, thickened, yellow or purplish brown; aecidia not 

 closely crowded, irregularly distributed over the spot, with, 

 however, a free central area, short, but not deeply immersed, 

 firm, the coarsely divided border widely and elegantly excurved; 

 spores subglobose, usually angular, epispore firm, smooth, 12- 

 15 (tt; spermagonia few, central, on both leaf -surf aces, reddish 

 orown. On Ambrosia trijida : Champaign, June. 



On Xanthium : Hypophyllous, very rarely also epiphyllous. 

 Spots not large, distant, scarcely thickened, yellowish, some- 

 times tinged purple; ascidia not densely crowded, irregularly 

 distributed or subcircinate, mostly irregular in outline, deeply 

 immersed and protruding little above the raised epidermal bor- 

 der, the margin pulverulent, rarely lobed and excurved; spores 

 subglobose or elliptical, often angular, epispore rather thin, 

 minutely tuberculate, about 15-18 ^; spermagonia few, central, 

 mostly above, minute, yellowish brown. On Xanthium stru- 

 iiKtriuiH : Champaign, June. This is much like the form on 

 SilpJiinin, and answers in some respects to yE. verbesina\ Schw., 

 and also to .E. tracheHifoliatum, Schw., but it is probably 

 neither. The ^Ecidinm is often followed by Puccinia xanthii, 

 Schw., and may be connected therewith. 

 17 



