Freeman : MINNESOTA UREDINE^-E. 551 



33. P. nardosmiae E. & E. Journ. Myc. i : 85. 1885. 



On Petasitcs palmata (Arr.) A. GRAY: St. Louis, (III) Jy. 

 1886, Holway 232. 



34. P. porphyrogenita CURT. Thiim. Myc. Univ. No. 545. 



1876. 



On Corntis canadensis L. : St. Louis, (III) Jy. 1886, Hol- 

 way 108; St. Louis, (III) Je. 1893, Sheldon 4622. 



35. P. hydrophylli PECK & CLINT. Rep. N. Y. St. Mus. Nat. 



Hist. 30: 54. 1879. 

 On Hydr&pkyllwm -virgin! cum L. : Hennepin, (III) My. 



1891, Sheldon 1968 and 1981 ; Meeker, (III) Je. 1892, 

 Frost 37 ; Ramsey, (III) My. 1892, Sheldon 1969 ; Aitken, 

 (III) Je. 1892, Sheldon 2072 ; - , (III) 1893, Sheldon 

 5803; Hennepin, (III) My. 1899, Freeman 310. 



36. P. tiarellae B. & C. N. A. Fungi, No. 549. 1881. 



On Mitclhi unda^L. : St. Louis, (Ill)Jy. 1886, Holway 62. 



37. P. halenise ARTH. & HOLWAY, Rep. Bot. Wk. in Minn. 



3: 30. 1886. 



On Tetragonanthus deflcxus (J. E. SMITH) KUNTZE : St. 

 Louis, (III) Jy. 1886, Holway 100. 



38. P. mesomegala B. & C. Grev. 3: 53. 1874. 



On Clintonia borcalis (AiT.) RAF. : St. Louis, (III) Jy. 

 1886, Holway 18. 



39. P. xanthii SCHWEIN. Syn. Fung. Car. Sup. 500. 1822. 

 Berkeley and Ravenel have described a variety ambrosia. 



The spores on Ambrosia do not, however, differ morpholog- 

 ically from those on Xanthiwn* 



QftXanthium canadense MILL. : Hennepin, (III) O. 1889, 

 MacMillan ; Brown, (III) Jy. 1891, Sheldon 861 and 

 1008; Carver, (III) Jy. 1891, Ballard 756; Lincoln, 

 (III) Ag. 1891, Sheldon 1262; Otter Tail, (III) Ag. 



1892, Sheldon 3898; Traverse, (III) S. 1893, Sheldon 

 7259; Hennepin, (III) S. 1898, Butters; Ramsey, (III) 

 Jy. 1899, Freeman 531 ; Houston, (III) Ag. 1899, Lyon 



458. 



Ambrosia trifida L. : Lincoln, (III) Ag. 1891, Sheldon 

 1266; Brown, (III) Ag. 1891, Sheldon 1227. 



Gymnoconia LAGERH. 



Separated from Puccinia on account of the aecidia, which 

 are destitute of a pseudoperidial wall and are at first covered 

 only by the epidermis of the host. 



