Description of American Uredine/e, I. 



By J. C. ARTHUR AND E. W. D. HOLWAY 



The following descriptions and synonyms of species and 

 accompanying critical notes are based upon the distribution of 

 dried specimens b}' the authors, issued under the title, Ure- 

 DiXE.^ ExsiccATAE ET IcoNES. This is intended to furnish a 

 convenient text for use in connection with the dried specimens 

 and illustrations, the latter being here reproduced, and it is in 

 no sense a monograph or revision. It is hoped that it will 

 also promote in other ways the study of this particularly inter- 

 esting group of plants. 



The series, of which this is the first number, will be con- 

 tinued until, it is hoped, all or nearly all the species of rusts of 

 North America have been included. The present installment 

 includes only Lcfto-urcdinecc. 



The numbers refer both to the packets of cxsiccatcE and to 

 the illustrations, the drawings being made in all instances 

 directlv from the material of the distribution. 



I. Uromyces RUDBECKEt Ai'th. & Holzv. (1884. Bull. la. 

 x\gl. Coll.. p. 184. ) On Rudbecl'ia laciuiata L.. Decorah, 

 la., Ilohcay. Plate L, Fig. i. 



Orig. Descr. "Sori on the under surface of the leaf, compact, confluent 

 into raised, mostly rounded, masses ^vith a depressed center, naked, 

 light brown; encircling epidermis obscure; teleutospores elliptical 

 to pear-shaped, smooth, pale golden brown, 9-1 SF ^^Y 20-30//; wall 

 thin; apex about 6fi thick, narrowed into a broad obtuse point, or 

 more rarely rounded, or broadly conical; pedicel rather broad, but 

 delicate, colorless, once to twice as long as the spore." 



Ills.. Burrill; Wis., Trelease; Neb., Bessey and Webber; 

 N. Dak. and Mont., Seymour, 

 Exsic. Ellis, N. A. F. 1439. 



