330 NATURAL HISTORY BULLETIN. 



III. Teleutosori amphigenous, oblong, pulvinate, early 

 naked, ruptured epidermis inconspicuous, blackish-brown; 

 teleutospores oval, very dark brown, rounded at both ends or 

 somewhat narrowed below, 18-25 by 28-40/A, wall medium 

 thickness, about 3/a, very slightly thickened above, smooth or 

 rarely roughened in the upper part, (not constricted at the 

 septum) pedicel moderately stout, firm, tinted, once to twice 

 the length of the spore. 



X. Amphisori amphigenous, resembling the teleutosori 

 but a little lighter brown; amphispores broadly obovate to 

 globose, of the same dark brown color as the teleutospores, 

 28-34 by 32-45/A, side-walls thick, $/a, much thicker above, 

 strongly papillate above, becoming less so toward the base, 

 pores 3, equatorial, inconspicuous, pedicel persistent, like that 

 of the teleutospores. 



EXSIC: 



Seymour and Earle, Econ. Fungi, 532a, 532$. 



Sydow, Uredineen, 1086. 



Ellis, N. Am. Fungi, 1051. 



Rabenhorst- Winter, Fungi Europaei, 3718. 



Griffiths, West Am. Fungi, 253. 



The amphispores of this species were the first form to attract 

 attention, being described as a species of Uromyccs. Not long 

 afterwards the supposed uredo form was described by one of 

 the present writers, first as an emendation to the original 

 description {Bull. Minn. Acad. Set. 2:36), and subsequently 

 as a species of Uredo { Uredo boutelouce Arth., in Bull. Ioxva 

 Agric. College for Nov. 1884: 164), some doubt having arisen 

 of the wisdom of the first assignment, as no teleutospores had 

 been found closely associated with it. The author of the 

 species has now ascertained beyond question that the host of 

 Uredo boutelouce is not a Bouteloua, but is Poa ftratensis and 

 the name, therefore, does not apply to the uredo of Puc. 

 vexans and is not a synonym of that species. 



About the time of this unfortunate error, it was shown by 

 Dr. W. G. Farlow, (1. c.) in comments upon a collection made 

 by one of the present writers and distributed in Ellis' N. x\m. 



