264 



A TEXT-BOOK OF BOTANY 



and the grain is the characteristic seed-like fruit. The 

 flowers occur in small close clusters, and associated with 

 them are peculiar bracts characteristic of the family 

 (Fig. 260). For example, these bracts form the so-called 



chaff of wheat and other 

 cereals, where they persist 

 and more or less envelop 

 the grain. These little 

 clusters of bracteate flow- 

 ers are arranged to form 

 either a loose and spread- 

 ing general cluster, as in 

 red top and oats (Fig. 

 262), or else a compact, 

 spike-like cluster, as in 

 timothy and wheat (Fig. 

 261). 



When the uses of 

 grasses are considered, it 

 becomes evident that this 



FlG. 260. Oats : A, part of a flower-cluster, is by far the most i 



showing the bracts, in the axils of which 4- qn 4. fomjlv n f rklflnt<5 tn 



flowers appear; B, a single flower, with tant 



its enveloping bract, three stamens, and man. It is possible to 



P S"^ZLo b r tW PlUm086 suggest only some of the 



conspicuous forms. 



(1) CEREALS. This group includes those grasses that 

 are cultivated for their seed-like fruits or grains, and they 

 represent the chief interest of agriculture. What cereals 

 mean as a food-supply for the world is too well known to 

 need explanation. The most extensively cultivated cereals 

 are as follows: 



Wheat. This is certainly the best known and most 

 valuable of all cereals. The original home of wheat is 

 unknown, for it has been cultivated from the very earliest 

 times. It is a crop peculiarly adapted to regions of cold 



