i^ 



230 1DJ Mycologia 



pears to be no noticeable difference between the pycnia and aecia 

 grown this year from telia on the true juniper and those grown 

 last year from telia on the true cedar, thus confirming the unique 

 character of this species of rust in growing upon hosts of the 

 two quite distinct sections of the genus Juniper us. 



18. Gymnosporangium nidus-avis Thax. on Juniper us vir- 

 giniana L., collected at Asheville, N. C, by the writer, was 

 sown March 22 on Amelanchier canadensis, without infection, 

 and at the same time on Crataegus Prmglei and Mains Iocnsis, 

 both giving rise to an abundance of pycnia April 6. The infec- 

 tion on Crataegus did not perfect aecia, but that on Mains ma- 

 tured aecia in abundance by April 2/. ::i 



The telia of this collection were on the main branches of a 

 tree thirty feet high, and when found were fully expanded. 

 They formed wavy masses standing out two centimeters or 

 more from the bark and extending in long lines of four or five 

 decimeters, like orange colored ruffles or frills. The appearance 

 was that of a large Treniella, and so unlike that of any Gymno- 

 sporangium before seen that not until it was examined under the 

 microscope after returning to Lafayette was it accepted as a rust. 

 It was found that the frills were the consequence of the large sori 

 forming in rows and cracking the bark longitudinally. 



19. Gymnosporangiiwi Betheli Kern, on Junipefus scopu- 

 lorum Sarg., collected in Colorado by Mr. E. Bethel, was sown 

 May 14 on Crataegus cerronis, and gave rise to pycnia May 22 

 in abundance, and to first appearance of aecia June 14, the aecia 

 being fully mature August 3. 32 



20. Gymnosporangium corxutum (Pers.) Arth., on Junip- 

 evus sibirica Burgsd., collected at Leland, Mich., by Mr. F. D. 

 Kern, was sown June 5, on Aronia nigra and Amelanchier erect a 

 with no infection, and at the same time on Sorbus americana, 

 giving an abundance of pycnia June. 15, but no aecia were formed 

 owing to the weakness of the host plant. Another sowing was 

 made from the same material June 7 on a cutting of Sorbus 

 aucuparia placed in water, giving a few pycnia June 18, but the 



31 For previous cultures see Jour. Myc. 14: 19. 1908. 



32 For previous cultures see Jour. Myc. 14: 23. 1908; and Mycol. 1: 240. 

 1909. 



