1902] THE UREDINEAi IN AMERICA 7 



spermatia obovate or oblong, about 3 by 5 /x. Aecidia hypophyl- 

 lous, or on petioles and fruit, in dense rounded groups, usually 

 on swollen and discolored spots; peridia cylindrical, often 

 elongated, margin lacerated ; aecidiospores obovate or elliptical, 

 22-36 by 33-37 /"» contents orange when fresh, becoming faintly 

 yellow when old, wall colorless, thin at the sides but greatly' 

 thickened at the obtuse apex, tuberculate. 



IL III. Sori hypophyllous, amphigenous on some hosts, 

 supercostal, very prominent, large, oblong, elongated on sheaths 

 and culms, ruptured epidermis attached in shreds or disappear- 

 ing, II, Uredosori pulverulent, at first bright orange, becoming 

 yellowish and indistinct ; uredospores obovate or elliptical, 

 22-30 by 33-44 II, contents orange when fresh, becoming faintly 

 yellow when old, wall colorless, thin at the sides but greatly 

 thickened at the rounded apex, prominently tuberculate, pores 

 obscure. III. Teleutosori pulvinate, blackish-brown; teleuto- 

 spores elliptical or oblong, 16-22 by 35-62 /i, dark brown, 

 slightly constricted at the septum, apex obtuse, thickened ; 



pedicel firm, slender, tinted, once to twice the length of the 

 spore 



Common throughout the United States and Canada east of the 

 Rocky mountains. On leaves, petioles, and fruiting inflorescence 

 of the various species of Fraxinus and Spartina ; spermogonia and 

 aecidia May to July, uredo in July and August, followed shortly ^ 

 by the teleutospores, w^hich persist through the winter and ger- 

 minate the next spring. Specimens have been examined as 

 follows : 



On Fraxinus lanceolata Borck. {F. viride Michx.) May 1871, O. I, 

 Ames. Iowa (/. C. Arthitr); July 1883,0. I, Spirit lake, Iowa (/. C. 



Wash 



1892, 



HartholomeTO 

 M 



Minn. (/. C. Arthur); May and June 1899, O. I. Lafayette, Ind. (grown 



from teleutospores on Spartina by the writer, /. C. Arthur) ; June 1899, I, 



Ames, Iowa {H. H. Hume) ; July 1899, I, Spirit lake, Iowa (/. C. Arthur) ; 



Aug. 1899, I, South Hero, Vt. (£. R. Jones); June 1900, O. I, Spirit lake, 



Iowa (/. C. Arthur); July 190 r, I, Crow agency, Mont. (237, /. W, Blank- 

 inship). 



