62 



Mycologia 



A. erecta, Crataegus cerronis, Philadelphus coronarius, and on 

 the last species once more April 12. The only infection was on 

 Amelanchier vulgaris, showing pycnia April 24, but failing to 

 mature aecia. Other sowings made in May were without re- 

 sults. The connection with aecia on Amelanchier had been pre- 

 dicted by Mr. Bethel from his field observations in Colorado 

 from 1907 to the present season, and also by Mr. A. O. Garrett 

 in Utah, 1910. The same kind of observation is recorded by 

 Tracy & Earle for southern Colorado in 1898.^^ The galls used 

 for these sowings were on small twigs, globoid, and from i to 2 

 cm. in diameter. This form, generally distributed under the 

 name of G. durum Kern, has recently been united by Dr. Kern^* 

 with G. Nelsoni Arth. On the type specimens of the latter the 

 galls are small, only 1-8 mm. in diameter, and hence not at first 

 readily identified with the large woody galls, which have been 

 called G. durum. 



All cultures heretofore reported in this series under the name 

 G. Nelsoni belong not to this species but to G. juvenescens Kern, 

 as stated in the report for 1910.^^ The latter is a species pro- 

 ducing witches' brooms, but not woody galls. 



4. Gymnosporangium Kernianum Bethel, on Juniperus ufah- 

 ensis (Engelm.) Lemmon, sent by Mr. Bethel from Paonia, Colo., 

 was sown April 7 on Amelanchier vulgaris, and Crataegus cer- 

 ronis, with infection only on the Amelanchier, showing pycnia 

 April 17, but not maturing aecia. Another sowing on Amelan- 

 chier vulgaris April 17 was without result, and the same was true 

 of another collection from Paonia, Colo., sown on the same day. 

 The failure to secure aecia makes it impossible to identify the 

 aecia of this species among the many forms occurring on Amelan- 

 chier, although it is doubtless already in the hands of collectors. 

 So far as the evidence goes it bears out Mr. Bethel's surmise^^ 

 regarding the aecial hosts. This culture is referred to by Kern^'' 

 in his monograph on the genus Gymnosporangium. 



5. Gymnosporangium effusum Kern, on Juniperus virginiana 



Greene, Plantae Bakerianae i : 19. 1901. 

 2* Bulk N. Y. Bot. Gardi. 7: 448', 470. 191 1. 



Mycol. 4 : 26. 1912. 

 ^® See Mycol. 3 : 158. 191 1. 

 -■'See Bull. N. Y. Bot. Garden 7: 449. 1911. 



