4 FIELD CROP PRODUCTION 



that varies slightly in some one or more characteristics 

 from the other individuals in the species. Such a group of 

 plants is called a variety. A variety, therefore, is a 

 group of individuals within a species that possesses 

 some variation from the species as a whole. As yet no 

 varieties have been developed from Kentucky blue-grass, 

 but examples of varieties in abundance may be had from 

 the grain crops, such as corn and wheat. Thus we find 

 many varieties of corn, such as Reid Yellow Dent, 

 Boone County White, Calico, and many others. These 

 varieties have some character or characters that dis- 

 tinguish them from corn in general. The color of the 

 grain, the size of the ear and plants, the length of season 

 required for growth, and similar variations are distin- 

 guishing variety characteristics.'^ Varieties, however, are 

 not so different from the other individuals of the species 

 as to form a separate and distinct species by themselves. 

 Thus Reid Yellow Dent and Boone County White, and 

 all other varieties of corn, are members of the corn species 

 Zea Mays. 



4. Genus. — If one examines closely all kinds of 

 grasses, it will be found that certain kinds bear a close 

 resemblance to Kentucky blue-grass, in the general appear- 

 ance, manner of growth, structure' of parts, the arrange- 

 ment of flowers, and the like.^ Thus such species as 

 Canada blue-grass. Rough-stalk meadow-grass, and 



'In presenting the scheme of classification of plants, the author has 

 used such general terms as "manner of growth," and " general appearance" 

 in referring to varietal and generic characteristics, viewing the subject 

 from the agronomist's point of view, as the discussion for elementary 

 students of the plants with which he deals does not necessitate going 

 into the intricate distinctions employed by the botanist. The term 

 " variety " is used in the agronomic sense, not as a sub-species as the 

 botanists use it. 



