60 MONTANA AGRICULTURAL COLLEGE SCIENCE STUDIES. 



Lesquerella Ludoviciana, Wats. Petals frequently purplish. 

 Wibanx, May 25, 1902; Great Falls, June 9, 1885, R. S. Williams; 

 Martinsdale, May 26, 1880, R. S. Williams. 



*Nasturtium Armoracia, Fries. A not infrequent escape fro its 

 cultivation. Helena, July 9, 1900; Bozeman, Aug., 1901. 



Physaria macrantha, n. sp. 



5-8 cm. high with a long, deeply penetrating root : petals 10-14 

 mm., long, bright yellow: fruit didymous and much inflated, often 

 large, 10-14 mm - diameter. In dry stony subalpine localities, 7-9000 

 ft. altitude, and appears to intergrade with P. didymocarpa, Gray, 

 which grows at lower elevations and has smaller (7-8 mm.) and paler 

 colored petals and smaller (7-10 mm.) fruit. 



Hills near Granite Butte, Sept., 1902, Owen Byrnes ; Midvale, 

 July 9, 1903, L. M. Umbach; Mt. Bridger, 8500 ft., July n, 1903; 

 Dewey, June 24, 1902. 



Sisymbrium decumbens, (Rydb.) ; Schoenocrambc decumbens, 

 Rydberg, Bull. Torr. Bot. Club, 31 1409. Separated from 3\ lini folium. 

 Nutt. "Melrose, 1895, Rydberg, 2671 ; Sheridan, 1895, L. A. Fitch." 



*Sisymbrium altissimum, L. The "Tumbling Mustard" is be- 

 coming a common and troublesome weed in many sections of the 

 state. Great Falls, July 10, 1900; La Salle, June 24, 1901, W. F. Jel- 

 lison; Belgrade, Oct. 20, 1904; Missoula, June 5, 1892. 



Sisymbrium canescens, Nutt. In the eastern plains, frequent. 

 Great Falls, R. S. Williams, May 24, i885;*Custer Station, May 30, 

 1890; Forsyth, June 29, 1898; Fergus Co., July 5, 1901, F. A. 

 Spragg. 



Sisymbrium incisum Californicum, (T. & G.) ; Sophia California. 

 Rydberg, Bull. Torr. Bot. Club, 29:238. Dewey, Beaverhead Co., 

 June 24, 1902. 



Sisymbrium viscosum, (Rydb) ; Sophia viscosa, Rydberg, Bull. 

 Torr. Bot. Club, 29:238. Distinguished from 5". incisum, Engelm. 

 by its viscid pubescence throughout and narrower siliques. 

 Deep Cr. Canyon, Big Belt Mts., Aug. 14, 1899. 



Smelowskia Americana, Rydberg, Bull. Torr. Bot. Club, 29:239. 

 The American forms of S. calycina, C. A. Meyer are separated under 

 this name. 



Thelypodium Nuttallii, Wats.? Some two feet high with 



