MICHIGAN WEEDS. 



349 



Fig. 97 (89). 



Sand Rocket. Diplolaxis muralis (L.) DC. 

 Annual, smooth or nearly so, branching from 

 the base, 30-60 cm. high; leaves oblong, toothed 

 or pinnatifid; flowers yellow, pods erect, linear, 

 terete. 



Introduced from Europe, and where it has 

 been found in Michigan, thrives and spreads 

 at an alarming pace. 



Fig. «>^ 9 



Worm-seed or Treacle, Mustard. Erysi- 

 mum chciranthoides L. An erect, minutely- 

 rough, annual, or winter annual, 20-00 cm. high; 

 leaves lanceolate, entirely or slightly dentate, 

 2-8 cm. long, the lower with slender petioles, 

 the upper sessile; flowers yellow, pedicels 

 spreading at about 45 degrees, the pods not 

 quite erect, but taking on uniform positions, 

 four-angled, smooth, 1-2 cm. long. 



Probably native to some portions of the 

 north central states and Canada. 



