244 NORTH AMERICAN FLORA [V01.UME 7 



I. Aecia amphigenous, gregarious, in annular or crowded groups 1-1.5 mm. across, on 

 discolored spots, short, cupulate or occasionally somewhat elongate, 0.1-0.2 mm. in 

 diameter; peridium colorless, the margin erose ; peridial cells rhomboidal, 26-32 m long, 

 overlapping, the outer wall rather thick, 6-8 ju, transversely striate, the inner wall thinner, 

 2-3 ju, somewhat striate, very moderately verrucose ; aeciospores globoid, 15-18 by 16-19 )u; 

 wall light-yellow or colorless, thin, Iju, finely verrucose. 



II. Uredinia amphigenous, scattered, roundish, 0.3-0.8 mm. across, early naked, some- 

 what pulverulent, cinnamon-brown, ruptured epidermis conspicuous; urediniospores 

 broadly ellipsoid or obovoid, 15-22 by 19-27 m ; wall golden-brown, 1.5-2/z thick, finely and 

 closely verrucose, the pores 4, equatorial. 



III. Telia amphigenous, scattered, oval or oblong, 0.5-1 mm. long, often confluent, 

 early naked, pulvinate, chocolate-brown, ruptured epidermis noticeable ; teliospores broadly 

 ellipsoid or obovate-ellipsoid, 16-24 by 23-32 m, slightly narrowed below, usually rounded 

 above; wall cinnamon-brown, 2-3 ju thick, thicker at apex, 4-7 /x, smooth ; pedicel hyaline, 

 once to twice length of spore. 



On Polygonaceae : 



Polygonum aviculareJ^.^ California, Connecticut, Delaware, Illinois, Indiana, Iowa, Kansas, 

 Maine, Massachusetts, Michigan, Minnesota, Nebraska, New Jersey, New York, North 

 Dakota, South Dakota, Utah, Vermont, Washington, Wisconsin ; Ontario. 

 Polygonum buxiforme Small, California, Colorado. 



Polygonum erectum, 1^., Connecticut, Delaware, Illinois, Indiana, Iowa, Mississippi, Mis- 

 souri, Nebraska, New Jersey, New York, North Carolina, Pennsylvania, South Dakota, 

 West Virginia, Wisconsin. 

 Polygonum Fowleri B. T^. Robinson, Maine ; Newfoundland. 

 Polygonum. m.ariiim.um. ly., I,ouisiana. 

 Polygonum, ram.osissim.um. Michx., Illinois, Iowa, Kansas, Minnesota, Missouri, Montana, 



Nebraska. 

 Polygonum sawatchense Small, Colorado. 

 Polygonum spergulariaeforme Meissn. , British Columbia. 

 Type locality : Europe, on Polygonum, aviculare. 



Distribution : Throughout the United States northward into Canada; also in Europe, Africa, 

 Asia, and Australia. 



Illustrations : Beitr. Krypt. Schweiz 22 : / 46 ; McAlpine, Rusts Austr. pi. 18, f. 150, 151. 

 ExsicCATi : Ellis, N. Am. Fungi 237 ; Ellis & Ev. Fungi Columb. 252, 1897, 1898, 2188; Seym. 

 & Earle, Econ. Fungi 361,362a, b, 363, 368, 369a, b, c; Kellerm. & Swingle, Kans. Fungi 50; D. 

 Griff. W. Am. Fungi 55, JJ.?; Sydow, Ured. 1807; Shear, N. Y. Fungi 77, 124; Earth. Fungi 

 Columb. 2994, 3097 ; Clements, Crypt. Form. Colo. 540; Brenckle, Fungi Dak. 72 ; Rab.-Wint. 

 Fungi Eur. 3628a, b, 3629a, b. 



44. Nigredo intricata (Cooke) Arthur. 



Uromyces intricaius Cooke, Grevillea? : 3. 1878. 



Uromyces Chorizanthis Ellis & Hark. Bull. Calif. Acad. 1 : 28. 1884. 



Uromyces Eriogoni Ellis & Hark. Bull. Calif, Acad. 1 : 29. 1884. 



Uromyces arizonicus Tracy & Gall. Jour. Myc. 4 : 20. 1888. 



Uromyces Gnaphalii Ellis & Ev. Erythea 1 : 204. 1893. 



Caeomurus arizonicus Kuntze, Rev. Gen. 3^ : 449. 1898. 



Caeom.urus Chorizanthis Kuntze, Rev. Gen. 3^ : 449. 1898. 



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



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



Caeomurus intricaius Kuntze, Rev. Gen. 3* : 450. 1898. 



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



0. P3xnia epiphyllous, gregarious, in small groups 0.4-0,6 mm. across, not conspicu- 

 ous, honey-yellow becoming somewhat darker with age, globoid, 112-128 m in diameter 

 by 100-112 ju high ; ostiolar filaments 65-80/* long. 



1. Aecia hypophyllous, gregarious, in circular groups 1-2 mm. across, crowded, usually 

 short, sometimes somewhat elongate, small, about 0.2-0.3 mm. in diameter ; peridium color- 

 less, the margin finely dentate ; peridial cells rhomboidal, 28-35 ju long, the outer wall rather 

 thick, 7-9 M, transversely striate, the inner wall somewhat thinner, 3-5 m, somewhat striate, 

 moderately rugose ; aeciospores globoid, 16-22 by 19-24 /x; wall pale-yellow or colorless, 



thin, Iju, finely verrucose. 



II. Uredinia chiefly epiphyllous, scattered irregularly, or occasionally in annular groups 

 2-3 mm. across, roundish, 0.5-0.8 mm. across, soon naked, pulverulent, slightly pulvinate, 

 light chestnut-brown , ruptured epidermis not conspicuous ; urediniospores broadly ellipsoid 

 or obovoid, 20-25 by 26-33 /x ; wall dark golden-brown, 1.5-2.5 ju thick, rather sparsely and 

 moderately echinulate, the pores 3-6, rarely as many as 8, scattered. 



