Kern : Studies in the genus Gymnosporangium 505 



been known from the western mountains for some time and it has 

 been assumed that the telial stage must also exist there.* Several 

 fine collections made by Professor E. Bethel in Colorado have 

 verified the correctness of this assumption. 



Gymnosporangium Ellisii (Berk.) Farl. in Ellis, N. Am. Fungi, 



271. 1879 



The connection between this Gymnosporangium and Roestcha 

 transformans Ellis has been accepted almost without question for 

 many years and there are reasons for believing it correct, but it 

 may be noted that the culture record is much less authoritative than 

 for most of the other species. Cultures were attempted by Thax- 

 ter in 1886 and an examination of his report in the Proc. Am. 

 Acad. 22 : 264 shows that as a result of the sowing of the Gym- 

 nosporangium on detached leaves of Pyrus (Arouia) arbutifoha, an 

 effect was said to be manifest in about eight days on the Pyrus 

 leaves but no roestelial form or even pycnia ever developed. So 

 far as the writer knows, this is the only published account referring 

 to cultures of this species. 



Gymnosporangum speciosum Peck, Bot. Gaz. 3: 217. 1879 



Although this species has been recognized for a good many 

 years all attempts to connect an aecial form with it have failed. 

 There is in its region no unattached species of RoesUlia known with 

 which it may be associated and there is not the slightest clue as to 

 what the other stage may be. 



Mart 



333- l8l 7 



Under this name is here included the telial form of Roesteha 

 Penicillata (Pers.) Fries, which has been usually referred to by 

 European writers as Gymnosporangium tremelloides Hartig, since 

 ^ proposed that name in 1882, and not the telial form oi Roestelia 

 cornuta (Pers.) Fries. A 



ken made bv the writer in Science 27 : 93 »• l 9° 8 - 



See Pammel, Bull. Iowa Experiment Station 84 s 3 2 - x 9°5- 



