64 



The seed-bearing flower-heads are sometimes on separate plants from 

 the pollen-bearing, and about hail their size. 



The seed is about i-8 inch long, rather conical, light brown, often 

 flattened. To destroy Canada Thistle, alternate a hoed crop with a heavy 

 smothering crop. 



Redroot Pigweed ( Amaran thus retroflexus ) is a coarse weed 

 often found in cultivated crops or gardens, oelonging to the same fam- 

 ily as the garden Celosia and the Amaranths. It is a leafy annual 

 with a strong reddish tap-root. When mature, the stem is very woody, 

 and the seed is surrounded by short sharp bracts. The minute flowers 

 produce very abundantly smooth, shining, black, lens-shaped seeds, 

 i-i6 inch across. 



Russian Thistle (Salsola Kali-tragus . 



