234 NORTH AMKRICAN FLORA [V01.UMK 7 



II. Uredinia amphigenous, small, oblong, 0.1-0.2 mm. wide by 0.3-1 mm. long, 

 tardily naked, dark cinnamon-brown, ruptured epidermis conspicuous ; urediniospores 

 ellipsoid or ovoid, 18-21 by 26-31 |U ; wall golden-brown, moderately thin, 1-1.5 /x, sparsely 

 and lowly echinulate, the pores 3 or 4, usually 4, equatorial. 



III. Telia amphigenous, small, oblong, 0.1-0.2 mm. wide by 0.3-1 mm. long or longer 

 when coalescing at ends, tardily naked (on some hosts indehiscent), somewhat pulverulent, 

 blackish-brown, ruptured epidermis conspicuous ; teliospores clavate-ellipsoid, 17-22 by 31- 

 53m, obtuse or acute at both ends ; wall light chestnut-brown, darker above, rather thin, 

 1-1.5 /x, thicker above, 3-7 /i ; pedicel tinted, sometimes 60 ju long. 



The species is composed of more or less sharply defined races {cf. Kleb. Wirtsw. Rostp. 325- 

 329. 1904), only one of which has been cultivated in America (cf. Jour. Myc. 13 : 199. 1907). 



On Cyperaceae : 



Scirpus americanus Pers. {S. pungens Vahl), Alabama, Delaware. 



Scirpus campesiris Britten, North Dakota, South Dakota. 



Scirpus fiuviatilis (Torr.) A. Gray (S. maritimus Jluvia tilts Torr.), Illinois, Iowa, Kansas, 



Nebraska, Ohio, South Dakota, Wisconsin. 

 Scirpus pacificus Britton, California. 

 Scirpus paludosus A. Nels., Nova Scotia. 

 Scirpus rodusius Fnrsh, lyouisiana. 



Scirpus validus Vahl {S. lacustris Bart, not L.) , Nebraska, Wisconsin ; Nova Scotia, Ontario. 

 Type locality : Marseille, France, on Scirpus mariiimus. 



Distribution : East of the Rocky mountains from Montana to Nova Scotia southward to 

 Louisiana and Florida, and in central California ; also in Europe. 



RxsiCCATi : Ellis & Ev. N. Am. Fungi 1861; Ellis &Ev. Fungi Columb. 1598, 2189; Barth. 

 Fungi Columb. 2995, 2996, 3196; Barth. N. Am. Ured. 196; D. Griff. W. Am. Fungi 74, 346; 

 Kellerm. Ohio Fungi 229; Carleton, Ured. hm..49; Rab. -Wint. -Paz. Fungi Eur. i9J2; Brenckle, 

 Fungi Dak. 120, 120a; Sydow, Ured. 2303. 



26. Nigredo minuta (Dietel) Arth. Result. Sci. Congr. Bot. 



Vienne 344. 1906. 



Uromyces mmuius Dietel ; Atk. Bull. Cornell Univ. 3 : 21. 1897. 



O and I. Pycnia and aecia unknown. 



II. Uredinia hypophyllous , scattered, small, oval or oblong, 0.2-0.4 mm. long, rather 

 early naked, cinnamon-brown, ruptured epidermis conspicuous; urediniospores broadly 

 ellipsoid, 10-15 by 15-19 ju; wall golden-brown, rather thin, about 1.5 )u, finely and rather 

 sparsely echinulate, the pores 2, occasionally 3, approximately equatorial. 



III. Telia hypophyllous, scattered, small, orbicular or oval, 0.1-0.4 mm. across, early 

 naked, pulvinate, blackish-brown, ruptured epidermis conspicuous ; teliospores obovoid or 

 oval, 10-17 by 20-25 )u, rounded or obtuse above, narrowed or rounded below ; wall chestnut- 

 brown or lighter, concolorous, 1.5-2 ju thick, thicker at apex, 5-9 ju, smooth ; pedicel colored, 

 short, about length of spore or less. 



On Cyperaceae : 



Carex gracilhma Schw., Wisconsin. 



Care X lanuginosa Michx., Indiana. 



Carex puhescens Muhl., Iowa. 



Carex triceps Michx., Florida, Mississippi, Texas. 



Carex virescensMxi^sX., Indiana. 



Carex sp,, Alabama. 

 Type locality : Auburn, Alabama, on Carex sp. 

 Distribution : Florida to Texas, northward to Indiana and Iowa. 

 Exsiccati : Sydow, Ured. 1003. 



27. Nigredo valens (Kern) Arthur. 



Uromyces valens Kern, Rhodora 12 : 125. 1910. 



O and I. Pycnia and aecia unknown. 



II. Uredinia chiefly hypophyllous, scattered, oval or oblong, 0.3-0.4 mm. wide by 0.5-1 

 mm. long, tardily naked, somewhat pulverulent, cinnamon-brown, ruptured epidermis con- 

 spicuous; urediniospores ellipsoid, 16-19 by 19-26/x ; wall cinnamon-brown, 1.5-2/i thick, 

 evenly and strongly echinulate, the pores 4, equatorial. 



III. Telia chiefly hypophyllous, scattered, oblong or linear, 0.2-0.4 mm. wide by 0.5-2 

 mm. or more long, rather tardily naked, pulvinate, chocolate-brown, ruptured epidermis 

 conspicuous; teliospores oblong-obovoid or obovoid, 16-23 by 26-39 ju, rounded or often 



