1902] THE UREDINE.^ IN AMERICA 3 



lucida to a uniform scale of 470 diameters, and all are in vertical 

 section, excepting three uredospores which are in transverse 

 section (see explanation of figs, j and 4). The pedicels are as 

 carefully drawn as the rest of the spore. 



I. Uromyces ACUMiNATUS Arth. 1883, May. Bull. Minn. Acad. 

 Sci. 2:35. 



Syn.: 1S83, July, Uromyces Spartina Farl. Proc. Amer, Acad. Sci. 



18: n. 



ExsiCC: Ellis, N. Amer. Fungi, 239"^ 1443"'. 



Sydow, Uredineen, 251 ^". 



Seymour and Earle, Econ. Fungi, 67'", 68'", 546'". 



O. I. Spermogonia and aecidia unknown. 



II. III. Sori epiphyllous, intercostal, linear, soon naked, 

 ruptured epidermis conspicuous, II. Uredosori yellowish, 

 inconspicuous; uredospores globose or broadly elliptical, large, 

 22-3 5/x in diameter, average 30^, wall golden yellow, thick while 

 immature, becoming thin, echinulate with low, stout points, pores 

 5 to 8, scattered. III. Teleutosori blackish-brown, sunken 

 between the nerves or protruding; teleutospores dark brown, 

 obovate or oblong-clavate, 15-22 by 25-40/*, apex darker, 

 acuminate or obtuse, or with two or more projections, much 

 thickened, 8-1 2/t, base narrowed, pedicel colored, firm, once to 

 thrice length of the spore, often shorten 



From Massachusetts to Illinois and Nebraska and northward ; 

 especiall}' abundant in the upper Mississippi valley. On leaves 

 of the several species of Spartina; the uredospores in July, soon 

 followed by the teleutospores, which persist through the winter 

 and germinate the following spring. Specimens have been 

 examined as follows : 



On Spartina cynosuroides {^)\^\\\6.. 1881. HI, Illinois (1326, A. B. 

 Seymoitr); Sept. 1882, III, Ft. Dodge. Iowa (type of Urom. acuminatus Arth., 

 J- C. Arthur); ^Qv. 1882, III, Decotah, Iowa {E. IV. D. Holway^; Dec. 

 1882, III, Spirit lake, Iowa (/. C. Arthur); July 1883, II, Spirit lake, 

 Iowa (/. C. Arthur) ; Sept. 1 883, III, Decorah, Iowa (Ellis, N. Am. Fungi, 1443. 

 E' W. D. Holivay); Dec. 1883, III, Spirit lake, Iowa (/. C. Arthur); Aug. 

 1884, HI, Bismarck, N. D. (Journey to Washington Territory, 297, ZqZ, A. 

 B. Seymour); Aug. 1884, HI, Valley city, N. D. (Journey to Washington 



