124 



THE SCIENCE OF LIFE. 



and an inferior perianth, (ovary superior,) as Lilies, 

 Rushes, and Palms ; 3. Incomplete, with imperfect flow- 

 ers, without a proper whorled perianth, as Screw-pines 

 and Arums. 



3. GRAMINE^:, the Grass Family, is one of the most 

 important orders in the vegetable kingdom, whether we 

 regard it as supplying food for man or herbage for ani- 

 mals. Grasses are found in all quarters of the globe ; 

 and are said to form about i-22d part of known plants. 

 There are about 4,000 species, and their structure is the 

 most simple of the higher forms of vegetation. Their 

 stems form protecting sheaths to the growing shoots, 

 and have alternate leaves. Their flowers, or glumes, 

 present many varieties, producing the distinctive char- 

 acters of families or tribes, and genera. Among the 

 grasses are the nutritious cereal 

 grains, as Wheat, (Triticum,) Oats, 

 (Avena^) Barley, (Hordeum,) Rye, 

 (Secale,) Rice, (Oryza,} Maize or In- 

 dian Corn, (Zea,) etc. Here, also, 

 are found various pasture grasses, as 

 Rye-grass, (Lotmm,) Timothy-grass, 

 (P/tleum,) Meadow-grass, (Poa,) etc. 

 (Fig. 49.) 



The cereal grains have been so 

 generally distributed by man that 

 all traces of their native country are 

 lost. They seem to be examples of permanent varieties 

 or races preserved by cultivation. 



The grains, or seeds, of many kinds are used for food, 

 since they contain a large amount of starch and gluten. 



FIG. 49. Wheat, Barley, 

 Meadow-grass. 



