102 MONTANA AGRICULTURAL COLLEGE SCIENCE STUDIES. 



*Madia filipes, Gray. An abundant weed introduced in waste 

 places in the extreme western part of the state. 



Troy, July 25, 1900; Thompson Falls, Aug. 8, 1901. 



*Madia dissitiflora, Torr & Gray; M. sativa disitiflcra, Gray. 

 A weed introduced from westward along- the railway. Thompson 

 Falls, Aug. 8, 1901. 



Petasites dentata, n. sp. 



P. sagittata, Gray, in Brew. & Wats., Bot. Calif., i -.407 ; Syn. Fl. 

 i: 376; not Tussilago sagittata, Pursh, Fl. N. Am. 531. In Pursh's. 

 description of the latter the radical leaves are said to be "oblongis 

 acutis sagitatis integerrimis, lobis obtusis," which cannot apply to 

 the common Rocky Mountain species with broadly ovate-hastate, 

 repand-dentate radical leaves meant by Gray. T. sagittata of Pursh 

 is from Hudson's Bay. M. L. Fernald of the Gray Herbarium 

 first noted this species as distinct from that described by Pursh, 

 but I do not find it elsewhere distinguished. 



Petasites sagittata, Rydberg, Flora, 484 and authors, as to the 

 Rocky Mountain species, is P. dentata above. 



Pyrrocoma Howellii, Rydberg, Flora, 382 is Aplopappus integrifolius 

 pumilus. 



Rudbeckia ampla, A. Nelson, Bull. Torr. Bot. Club, 28:234. 

 Appears to include all the Rocky Mountain R. laciniata, L. 



Rudbeckia laciniata, Rydberg, Flora, 416, is the last. 



Senecio alpicola, Rydberg, Flora, 447, is S. saxosus, Klatt. (J. 

 M. Greenman). 



Senecio altus, Rydberg, Flora, 443, is 5'. sphaeroccphalus, Greene. 

 (J. M. Greenman). 



Senecio atriapiculatus, Rydberg, Flora, 442 ; apparently identical 

 with S. Hookeri, Torr. & Gray. (J. M. Greeman). 



Senecio Balsamitae, Rydberg, Flora, 446 is S'. flavovirens, Rydberg. 



Senecio debilis, Nutt. ; 5. nephrophyllus, Rydberg, 446? (J. M. 

 Greenman). Fair Grounds, Helena, July 23, 1898, E. N. Brandegee; 

 Big Blackfoot River, July 13, 1883, W. M. Canby. 



