JACKSON: UREDINALES OF OREGON 223 



On Malaceae: I. 



Sorhiis occidentalis (S. Wats.) Greene — North slope Mt. Jefferson, 

 along trail to Hanging Valley, Aug. 15, 1914, H. P. Barss & G. B. 

 Posey, 139s; Columbia Highway, Multnomah Co., Aug. 19, 1916, 

 J. R. Weir, 2^9. 

 On Juniperaceae: HI. 



Juniperus sihirica Burg. — North slope Mt. Jefferson, Aug. 26, 

 1916, H. P. Barss, jjpp. 



The genetic connection of the forms of this alpine species has 

 been abundantly demonstrated by European investigators, first by 

 Hartig (Lerb. Baum-Kr. 133. 1882), and later by many others. 

 Arthur in 191 1 (Mycol. 4: 57. 1912), using telial material from /. 

 sibirica collected in Colorado, succeeded in obtaining infection result- 

 ing in pycnia only on Sorhus americana. The species is known in 

 America only from the Rocky and Cascade Mountains of the United 

 States and Canada. 



38. GyxMnosporangium juvenescens Kern, Bull. N. Y. Bot. Gard. 



7: 448. 1911. 

 On Malaceae: I. 



Anielanchier sp. — Hurricane Creek, Wallowa Co., Julv 24, 1897, 

 E. P. Sheldon, 8622. 

 On Juniperaceae: HI. 



Juniperus scopuloruni Sarg. — ^W^hite Pine, Baker Co., Aug. 191 5, 

 J. R. Weir, 169. 



This species causes witches' brooms on the telial host somewhat 

 similar to the eastern G. nidus-avis Thax. 



Arthur has repeatedly cultured it, showing that the aecia occur 

 on Amelanchier and Sorhus (Jour. Myc. 13: 203. 1907; 14: 18. 

 1908; Mycol. 1:239. 1909; 4:195. 1912). 



39. Gymnosporangium Kernianum Bethel, Mycologia 3: 157. 191 1. 

 On Juniperaceae: HI. 



Juniperus occidentalis Hook. — Redmond, Crook Co., July 2, 1914, 

 1392, May 15, 1915, jjpo. 



The above specimens are somewhat doubtfully referred to this 

 species. The witches' brooms are large and open, sometimes reaching 

 2-3 feet in diameter. The teliospores are somewhat more tapering 

 at the apex than is typical for the species and average shorter and 

 somewhat narrower, 19-22 by 45-65 ju. The only aecia collected in 

 the vicinity are properly referred to G. Harknessianum. There was 

 no very direct field evidence, and unless the above collections repre- 

 sent an undcscribed form there is little possibility that the two can 

 be genetically connected. Arthur (Mycol. 4: 62. 1912) has cultured 



16 



