230 



Mycologia 



pears to be no noticeable difference between the pycnia and aecia 

 grown this year from teUa 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 Jiiniperiis. 



18. Gymnosporangium nidus-avis Thax. on Juniperns vir- 

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

 sown March 22 on Amelanchicr canadensis, without infection, 

 and at the same time on Crataegus Pringlei and Mains loensis, 

 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 27.^^ 



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 Tremella, and so unlike that of any Gymno- 

 sporanghim 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. Gymnosporangium Betheli Kern, on Junipetus scopn- 

 loriim 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.^- 



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

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

 Kern, was sown June 5, on Aronia nigra and Amelanchier ere eta 

 with no infection, and at the same time on Sorhus 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 Sorhus 

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



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

 ^- For previous cultures see Jour. Myc. 14: 23. 1908; and Mycol. i: 240. 

 1909. 



