WEEDY GRASSES 165 



awns or bristles an inch or two long. These heads 

 break up and behave in the same manner as barley grass 

 described above. Squirrel-tail grass is troublesome in 

 alfalfa fields and in irrigated meadows. The pieces of 

 the heads with the spreading beards are blown about 

 sometimes in great quantities. The species has extended 

 eastward and is locally abundant as far east as Illinois. 



Two other species of Hordeum, one annual (H. pusil- 

 lum Nutt.) the other perennial (H. nodosum L.), are 

 often abundant in open ground, but are not serious 

 pests. They have small cylindric heads with short 

 upright bristles. The heads break up into joints. 

 These species are usually only a few inches to a foot high. 



Foxtail (species of Chaetochloa. See page 122). The 

 two common species in the Northeastern States are green 

 foxtail (C. viridis (L.) Scribn.), with a green head 

 slightly narrowed above, and yellow foxtail (C. lutescens 

 (Weigel) Stuntz, C. glauca of authors) with a somewhat 

 long yellow head that is not narrowed above. These 

 grasses are often abundant in neglected fields but are 

 easily eradicated by culture methods. In the South, 

 especially in Florida, there is a perennial species (C. 

 geniculata (Lam.) Millsp. & Chase) that closely re- 

 sembles yellow foxtail. 



Sandbur (Cenchrus pauciflorus Benth.). This well- 

 known annual grass is common on sandy soil throughout 

 the eastern half of the United States. The prickly burs 

 with backwardly roughened spines are very trouble- 

 some. In the South a second species (C. echinatus L.) 

 is common. The burs of this are scarcely so hard as 

 those of the other. Both species are also known as bur 

 grass. The first has been called C. caroliniana. 



