72 



Fig. 27. 

 Yellow Daisy, Cone-Flower, Black-eyed Susan, or Niggerhead. 



Rudheckia hirta, (L). 



A biennial and sometimes annual weed found in pastures and 

 meadows. It grows about 1 to 3 feet high. The stems are sparingly- 

 branched and very bristly. The leaves are thick, hairy, oblong and 

 tapering towards the point. The flower is about" 1 in. across, with 

 orange yellow rays or petals (10 to 20 in number) and dark purple 

 brown discs almost spherical or cone-shaped. The seeds are dark 

 brown, almost black, four angled, and about ^ in. long, with no pappus, 

 or tuft of hair (Fig. 27, a). An average plant produces about 2,000 

 seeds. 



Time of flowering, June-August. 



Time of seeding, July-September. 



Dispersal — as an impurity in seed grain. 



Eradication. It can generally be killed by mowing, but it is 

 sometimes necessary to break up meadow or pasture land, as 

 suggested in note to Mr. Rennie's method of cleaning land (see page 

 16), and follow with a hoed crop. If this is well cared for, it will 

 destroy all Cone-flowers. 



