170 



AGRONOMY 



Green amaranth (Amamnthus kybridut). This is also known 

 as redroot and pigweed. It grows to the height of several feet, 

 with broad coarse leaves topped by a dense pyramid of green- 

 ish flowers. It is a most abundant and well-known weed, but 



is easily exterminated. 



Tumbleweed (Amaran- 

 thus albus). Before the 

 advent of the so-called 

 Russian thistle this was 

 the best-known tumble- 

 weed. It is a rather low 

 plant with branches dis- 

 posed in globular form. 

 When mature, the whole 

 plant separates from the 

 root and is blown about 

 the country, scattering 

 the minute seeds as it 

 goes. 



Pigweed ( Chenopodium 

 album). This weed is 

 also known as lamb's 

 quarters. It is a pale 

 green plant with some- 

 what triangular leaves 

 that are whitened by a 

 mealy deposit, and is thus easily recognized. It is a close ally 

 of the beet and spinach and is often eaten as a pot herb. 



Russian thistle (Salsola trains'). This plant is in no sense 

 a thistle, being more closely related to the pigweeds. It is 

 extremely prickly, and from this circumstance its name is 

 derived. It is another of the tumbleweeds and in conse- 

 quence spreads rapidly. It is well known in the Middle West, 

 where it was accidentally introduced during the latter part of 



Photograph from American Steel and Wire Co. 



FIG. 119. The common plantain 



