JACKSON: UREDINALES OF OREGON 223 
On MaAtacese_E: I. 
Sorbus occidentalis (S. Wats.) Greene—North slope Mt. Jefferson, 
along trail to Hanging Valley, Aug. 15, 1914, H. P. Barss & G. B. 
Posey, 7395; Columbia Highway, Multnomah Co., Aug. 19, 1916, 
J. R. Weir, 279. 
On JUNIPERACEAE: ITI. 
Juniperus sibirica Burg.—North slope Mt. Jefferson, Aug. 26, 
Eto. il. P..Barss, 3300. 
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 r911 (Mycol. 4: 57. 1912), using telial material from J. 
stbirica collected in Colorado, succeeded in obtaining infection result- 
ing in pycnia only on Sorbus americana. The species is known in 
America only from the Rocky and Cascade Mountains of the United 
States and Canada. 
38. GYMNOSPORANGIUM JUVENESCENS Kern, Bull. N. Y. Bot. Gard. 
V=445. IOUL. 
On Mataceae: I. 
Amelanchier sp.—Hurricane Creek, Wallowa Co., July 24, 1897, 
E. P. Sheldon, 8622. 
ON JUNIPERACEAE: III. 
Juniperus scopulorum Sarg.—White Pine, Baker Co., Aug. 1915, 
J. R. Weir, 1609. 
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 Sorbus (Jour. Myc. 13: 203. 1907; 14: 18. 
1908; Mycol. 1: 239. 1909; 4: 195. I9I12). 
39. GYMNOSPORANGIUM KERNIANUM Bethel, Mycologia 3: 157. I9II. 
ON JUNIPERACESE: III. 
Juniperus occidentalis Hook. ia, Crook Co., July 2, 1914, 
1392, May 15, 1915, 3390. 
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 u. 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 undescribed form there is little possibility that the two can 
be genetically connected. Arthur (Mycol. 4:62. 1912) has cultured 
16 
