CHAPTEE XXII. 



The Classifloation of Plants.* 



256. Natural Groups of Plants. — One does not need to 

 be a botanist in order to recognize the fact tbat plants 

 naturally fall into groups which resemble each other pretty 

 closely, that these groups may be combined into larger ones 

 the members of which are somewhat alike, and so on. Eor 

 example, all the bulb-forming spring buttercups ^ which grow 

 in a particular field may be so much alike in leaf, flower, and 

 fruit that the differences are hardly worth mentioning. The 

 tall summer buttercups ^ resemble each other closely but are 

 decidedly different from the bulbous spring-flowering kind, 

 and yet are enough like the latter to be ranked with them as 

 buttercups. The yellow water-buttercups * resemble in their 

 flowers the two kinds above mentioned but differ from them 

 greatly in habit of growth and in foliage, while still another, 

 a very small-flowered kind,^ might fail to be recognized as a 

 buttercup at all. 



The marsh marigold, the hepatiea, the rue anemone, and 

 the anemone all have a family resemblance to buttercups,* 

 and the various anemones by themselves form another group 

 like that of the buttercups. 



257. Genus and Species. — Such a group as that of the 

 buttercups is called a genus (plural genera), while the various 

 kinds of which it is composed are called species. Familiar 

 examples of genera are the Violet genus, the Rose genus, the 

 Glover genus, the Golden-rod genus, the O0,k genus. The 

 number of species in a genus is very various, — the Kentucky 



1 See Warming and Potter Systematic Botany or Kerner and Oliver, vol. 11, pp. 

 616-790. 2 B. bulbosus. ^ R. acris. * H. nmltijidus. " R. abortivus. 

 fl Fresh specimens or lierl)arium specimens "Will sliow this. 



