Some Alaskan and Yukon Rusts. 235 



Puccinia rubefaciens Johanns., on Galium boreale L., a 

 rust common to both hemispheres. 



Aecidium Allenii CUnt., on Shepherdia canadensis (L.) 

 Nutt. This is a heretoecious form of wide distribution in North 

 America, and probably belongs to some grass rust, indications 

 pointing to an unnamed form on Calamagro^tis, Agropyron and 

 Bromus, hut no cultures have yet been made. The most northern 

 station heretofore known for it is Banff, Alberta. 



Mclampsora RihcsH'Salicum Bubdk (Uredo conJJuens Pers.), 

 II on Salix glauca L. The host was determined by Dr. F. V. 

 Coville, November, 1910. This is probably a common and 

 widely distributed species, but very few sporophytic collections 

 can be referred to it with certainty. It is a mountainous form 

 extending through a wide range of latitude in both the Old and 

 New World. The specimen in hand is scanty, but seemingly 

 characteristic. 



Melampsoropsis leduola (Peck) Arth. {Chrysomyxa ledicola 

 Lagerh.), II on Ledum groenlandicum Oeder. This abimdant 

 American rust has been collected on the same host in Greenland 

 (in 1886), and at Fort Wrangell, Alaska (in 1883, by Thomas 

 Meehan), and also on Ledum palustre at Turnavik island, 

 Labrador (in 1896, by the Cornell-Peary expedition), and at 

 Virgin Bay, Alaska (in 1899, by Wm. Trelease of the Harriman 

 expedition). It is evidently a common Arctic species, ranging 

 south to the northern border of the United States. 



Peridermium boreale Arth. & Kern, on Picea candensis (Mill.) 

 B. S. P. This little known and ill defined species has not be- 

 fore been reported north of Banff in British Columbia. The 

 leaves on the specimen have fallen from the stem in drying, but 

 otherwise the collection is typical of the species. 



3. Ccast Arctic Species, collected between Aug. 20 and 

 Sept. 1 at Nome, less than a hundred and fifty miles south of 

 the norrowest part of Bering strait. This is within the region 

 from which Puccinia laurentiana and Melampsora alpina have 

 been reported as mentioned above. 



Puccinia septentrionalis Juel.IIand III on Polygonum vivi- 

 parum h. This species has also been found in Newfoundland 

 by Rev. Waghorne, and its aecia, which occur on Jhalictrum 

 alpimim, were collected July 28, 1904, at Kadiak, on the southern 



