Parasitic Fungi of Illinois. 231 
On Eupatorium. Hypophyllous. Spots distinct, usually 
few, conspicuous, yellow; acidia irregularly clustered or some- 
what circinate, short, irregularly split and moderately recurved, 
soon pulverulent; spores subglobose, epispore rather thin, mi- 
nutely tuberculate, 18-20 »; spermagonia several, scattered, 
above, honey-yellow. On Eupatorium perfoliatum: McLean, 
July 11, 2424. 
On Silphinwn: Hypophyllous, and often also epiphyllous. 
Spots distinct, {usually widely scattered, not large, yellow, 
ecidia ; irregularly (associated, scarcely crowded, deeply im- 
mersed, and but slightly projecting above the raised epidermal 
border, margin many times split or pulverulent, little excurved; 
spores subglobose, often angular, 11-15 »; spermagonia rather 
few, conspicuous, reddish brown, central, on both sides of leaf. 
On Silphium integrifolium: McLean, May 3, 4852. S. terebin- 
thinaceum: McLean,tMay 30, 4825, June 23, 5274, July 2, 2420, 
July 11, 2421. SS. laciniatwm: McLean, June, coll. C. A. Hart. 
On Ambrosia: Hypophyllous. Spots large, often conflu- 
ent, scarcely thickened, yellow or purplish brown; excidia 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 »; spermagonia few, central, on both leaf-surfaces, reddish 
orown. On Ambrosia trifida: Champaign, June. 
On Xanthium :: Hypophyllous, very rarely also epiphyllous, 
Spots not large, distant, scarcely thickened, yellowish, some- 
times tinged purple; scidia 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- 
marium: Champaign, June. This is much like the form on 
Silphium, and answers in some respects to 2. verbesine, Schw., 
and also to 4’. tracheliifoliatum, Schw., but it is probably 
neither. The cidium is often followed by Puccinia xanthii, 
Schw., and may be connected therewith. 
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