CATALOGUE Of CANADIAN PLANTS. -17 



(155.) S. incisum, Engclm. var. Hartwcgianum, Watson. 



>S'. canesccns, Beiitli. PI. Bourgeau ; 254 in part. 

 (.^) S. canescen>^, var. brevipes, Torr. & Gray Fl. I., 92. 



Tliits species has boon confounded with S. canescens until a recent 

 date, and hence Bourgeau is found to include it with *S^. canescens. 1 

 have found this species to be the common form on the southern phiins 

 west of Moose Jaw Creek, X. W. T., and in the dry interior of British 

 Columbia. 



Var. fllipes, Gray Fl. Fendl, 8. 



This form gathered at Yale, B. C, is identical with one found by 

 Lyall on the southern boundary of British Columbia. {Macoiin & 

 Hill.) 



Collectors are requested to preserve complete specimens of the four 

 forms mentioned above. 



(156.) S. acutangulum, DC. 



A native of southern Europe. Naturalized in California and brought 

 from thence to the vicinity of New Westminster, British Columbia. 

 This species is No. 145 of my catalogue. 



(157.) S. humile, C. A. Meyer. 



Eocky Mountains, Lat 52°-57°. {Brwmmond.) About the Mackenzie 

 Eiver, Lat. 60°-68°. (Richardson.) 



(158.) S. salsugineum, Pall. 



Turritis diffusa, Hook. Fl. I., 41. 

 Shores of the Arctic Sea. {Richardson.) 



47. BRASSICA, Tourn. (TRUE MUSTARD.) 



(159.) B. Sinapistrum, Boiss. Wild Mustard. 



Sinapis arvensls, Linn. Torr. & Gray Fl. I., 99. 



Introduced from Europe. A vile weed in cultivated fields and waste 

 gi-ounds from New Brunswick throughout Quebec and Ontario. 

 Between Brighton and Toronto, on the line of the G. T. E.. many fields 

 during June are quite yellow with the flowers of this pest. Its seeds 

 retain the power of germination for a long time, and after it once gets 

 a footing on the soil years must elapse before the ground is freed from 

 them. 



