841 Illinois State Laboratory of Natural History. 



given to the latter, P. Aster is, Duby, P. Tripolii, Wallr. (Flora 

 Crypt. Germ. [1831-3] II. p. 228), and P. Asteris, Fckl. (Syrab. 

 Mycol. [1875] p. 53), which have been pronounced synonyms 

 by several botanists, and from the material and descriptions at 

 hand it is impossible to separate from these the American 

 forms. Schroter (Hedw. XIV. [1875] p. 109), after an exam- 

 ination of original specimens, confidently declares that the 

 forms are specifically identical. Cooke (Grevillea III. [1875], 

 p. 169) seems to regard Schweinitz's species as distinct from 

 the European plant, though not supposing P. Gerardii, Peck, 

 specifically different from the former. After careful compari- 

 son of specimen s ; all are here referred, as may be seen, to the 

 species called Puccinia Aster-is by Duby. 



P. silphii, Schw. 



III. Hypogenous; spots scabious, numerous, scattered, 

 concave, with a raised rim; sori very prominent, wart-like, com- 

 pact, dull grayish brown; spores irregular, oblong-clavate, con- 

 spicuously and angularly pointed, firm, dark colored, but not 

 thick walled, smooth, contents granular, 13 by 40 p- pedicel 

 tinted, firm, about the length of the spore. The leaves are 

 often thickly spotted and scarred by the fungus, and large 

 patches of sori occur also on the stems. 



Spots rather small, purple ; sori thick, pulvinate, confluent, aggre- 

 gated, black; spores compact, of uniform color. Schweinitz N. Am. 

 Fungi, No. 2929, p. 296. 



On Silphium terebinthinaceum : McLean, June 23, 5275. 

 S. integrifolium .-McLean, June 23, 5276, July 14, 5536, July 16, 

 2338, July 26, 2382; Champaign, Aug. 13, 1039; McHenry, 

 Aug. 26, 1322, Aug. 27, 1337, Aug. 31, 1389, Sept. 1, 1408; La- 

 Salle, Sept. 16, 1558. 8. perfoliatum: McLean, May 30, 4823; 

 June 19, 5265, July 17, 5579; Adams, June 30, 5368; McHenry, 

 Aug. 24, 1272; Lee, Sept. 9, 5763. 



P. xanthii, Schw. 



III. Hypophyllous. Sori small, mostly closely clustered 

 in spots or patches; spores smooth, oblong, evidently constrict- 

 ed, apex slightly thickened, round, or beak-like, 15-21 by 

 36-51," ; pedicel slightly colored, usually shorter than spore. 



