222 BROOKLYN BOTANIC GARDEN MEMOIRS 



lamette Valley on the incense cedars planted for ornament and, in 

 certain cases, will become a serious menace to cultivated pears and 

 quinces. 



The life history of the species was first worked out by Arthur 

 (Mycol. i: 252. 1909; 4: 57. 1912). He succeeded in showing 

 that aecia occurred on Crataegus and Amelanchier. The telial material 

 used for the cultures was collected at Eugene, Oregon, by Prof. A. R. 

 Sweetzer. The writer has also studied this species in some detail 

 (Phytopath. 4: 261-269. 1914; Ore. Expt. Sta. Biennial Crop Pest 

 Rep. II: 204-212. 1915) and has reported the results of culture 

 work and field observations. Similar work is also briefly reported by 

 O'Gara (Science N. S. 39: 620-621. 1914). The previous records of 

 the occurrence of this species on Malus floribundus Siebold and Sorhiis 

 samhucifolia Roem. made by the writer (1. c.) should be corrected to 

 read Pyriis ioensis and 5. aucuparia respectively. For the correct 

 determination of these hosts the writer is indebted to Prof. W. W. 

 Eggleston . 



This species has since been successfully cultured in the greenhouse 

 on Pyriis sinensis by Prof. H. P. Barss. The writer, using aecial 

 material on quince, the result of infection experiments made in 1914, 

 has obtained sparing infection on Lihocedrus resulting in telia which 

 matured in February 191 5. The trees were kept in the greenhouse 

 at the Oregon Agr. College. 



36. Gymnosporangium Harknessianum (Ell. & Ev.) Kern, Bull. 



N. Y. Bot. Card. 7: 441. 1911. 



Roestelia Harknessiana Ell. & Ev. Kern, Bull. Torrey Club 34: 

 462. 1907. 

 On Malaceae: I. 



Amelanchier alnifolia Nutt. — Redmond, Crook Co., July 2, 1914, 

 I393>' Fort Rock, Lake Co., Oct. 10, 1915, Wendover, jj 75. 



This very interesting species has otherwise been reported only 

 from northern California. The telia form is unknown. In the col- 

 lection made by the writer listed above, the aecia occurred only on 

 fruits and twigs. There was every evidence that this fungus is 

 perennial. Some of the specimens show fresh aecia on branches having 

 four annual rings, surrounding or extending from cankered areas 

 bearing evidence of old aecial cups. There is slight hypertrophy. 

 The branches are frequently girdled and killed. 



37. Gymnosporangium juniperinum (L.) Mart. Fl. Crypt. Erlang. 



333- 1817- 

 Tremella juniperina L. Sp. PI. 1157. 1753. 



