226 NORTH AMERICAN FLORA [V01.UME 7 



On Poaceae ; 



Aristida basiramea Engelm., Kansas, Nebraska. 



Aristida dichotoina Michx., Arkansas, Kansas, Kentucky. 



Aristida oligantha Miclix., Kansas, Texas. 



Aristida purpurascens Poir., Alabama, Kentucky, New Jersey. 



Aristida purpurea Nutt., Nebraska. 

 Type locality : Wakeeney, Kansas, on Aristida oligantha. 



Distribution : Montana south to Texas and Alabama, and from New Jersey south to South 

 Carolina. 



Illustrations : Bull. Lab. Nat. Hist. Univ. Iowa 5 : pi. l,f. 45a, b. 



ExsiccATi: Ellis & Ev. N. Am. Fungi 1829 ; Ellis & Ev. Fungi Columb. 1469, 1475,2181; 

 Carleton, Ured. Am. 26; Earth. Fungi Columb. 2390, 2892 ; Rav. Fungi Am. 483 ; Vesterg. Micr. 

 Rar. Sel. 1052a, b; Arth. & Holway, Ured. Exs. Ic. 45a, b. 



8. Nigredo minima (Davis) Arth. Result. Sci. Congr. Bot. 



Vienne 344. 1906. 



Uromyces minhnus Davis, Bot. Gaz. 19 : 415. 1894. 

 Caeomurus minimus Kuntze, Rev. Gen. 3^ : 450. 1898. 



O and I. Pycnia and aecia unknown. 



II. Uredinia hypophyllous, scattered, oval or oblong, small, early naked, cinnamon- 

 brown, only few seen; urediniosporesgloboidor subgloboid, 13-20 by 15-22 ju; wall cinnamon- 

 brown, 1.5-2 /x thick, strongly and sharply verrucose-echinulate, the pores 2-4, equatorial. 



III. Telia hypophyllous, scattered, oblong or linear, about 0.1 mm. wide by 0.3-1 mm. 

 long, early naked, dark chocolate-brown, pulvinate, ruptured epidermis not noticeable; 

 teliospores globoid or obovoid, 12-19 by 14-23/*; wall dark chestnut-brown, with a slightly 

 paler umbo, rather thin, 1-1.5 m, the apex very much thickened, 5-9 /x, smooth; pedicel 

 moderately stout, firm, slightly colored, about length of spore. 



On Poaceae : 



Muhlenbergia com.ata (Thurb.) Benth., Oregon. 



Muhlenbergia racemosa (Michx.) B.S.P. (M. glomerata Trin.), Oregon. 



Muhlenbergia sylvatica Torr., Wisconsin. 

 Type locality : Kenosha County, Wisconsin, on Muhlenbergia sylvatica. 

 Distribution : Wisconsin and northern Oregon. 

 Illustrations : Bull. Lab. Nat. Hist. Univ. Iowa 5 : pi. l,f. 48a. 

 ExsiCCATi : Ellis & Ev. N. Am. Fungi 1811, 3240; Rab.-Wint.-Paz. Fungi Eur. 3833a; Arth. 



& Holway, Ured. Exs. Ic. 48a. 



9. Nigredo Halstedii (De-Toni) Arthur*. 



Uromyces digitatus Halsted, Jour. Myc. 3 : 138. 1887. Not U. digitatus Wint. 1886. 



Uromyces Halstedii De-Toni, in Sacc. Syll. Fung. 7 : 557. 1888. 



Uromyces Halstedii Ludw. Bot. Centr. 37 : 120. 1889. 



Caeomurus Halstedii Kuntze, Rev. Gen. 3^ : 450. 1898. 



Nigredo digitata Arth. Result. Sci. Congr. Bot. Vienne 343. 1906. 



O and I. Pycnia and aecia unknown. 



II. Uredinia hypophyllous, scattered, small, linear or oblong, 0.2-0.5 mm. long, rather 

 tardily naked, somewhat pulverulent, cinnamon-brown, ruptured epidermis noticeable ; 

 paraphyses intermixed with the spores, mostly capitate, 12-21 by 36-56 ju, the wall nearly or 

 quite colorless, thin, about l;u or less, slightly thicker above, smooth; urediniospores 

 ellipsoid or obovoid, 15-21 by 21-28 m ; wall cinnamon-brown, thin, 1-1.5 /x, evenly and rather 

 finely echinulate, the pores 3 or 4, equatorial. 



III. Telia chiefly hypophyllous, scattered, oblong or linear, 0.1-0.2 mm. wide by 0.5- 

 1.5 mm. long, rather tardily naked, pulvinate, very dark blackish-brown, ruptured epi- 

 dermis conspicuous; teliospores broadly cuneiform, 15-23 by 19-27 m; wall dark chestnut- 

 brown, paler below, rather thin at the sides, 1-1.5 ju, smooth, the apex greatly thickened and 

 covered with numerous digitate projections 3-5^ long; pedicel tinted, slender, about as 

 long as the spore. 



On Poaceae : 



Homalocenchriis oryzoides (I^.) Poll. {Phalaris oryzoides I^., Leersia oryzoides Sw.), 



Delaware, South Dakota. 

 Homalocenckrus virginicus (Willd.) Britton {Leersia virginica Willd.), Alabama, Iowa, 

 Ivouisiana, Wisconsin. 

 Type locality : Ames, Iowa, on Leersia virginica. 



Distribution : South Dakota and Delaware southward, to Alabama and I^ouisiana. 

 Illustrations : Bull. Lab. Nat. Hist. Univ. Iowa 3 : pi. 4,f. 43a. 



Bxsiccati : Ellis & Ev. N. Am. Fungi 2227 ; D. Griff. W. Am. Fungi 50; Arth. & Holway, 

 Ured. Kxs. Ic. 43a. 



