CHAPTER XXII. 
The Classification of Plants.! 
256. Natural Groups of Plants. —One does not need to 
be a botanist in order to recognize the fact that 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. For 
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 hepatica, 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 
Clover genus, the Golden-rod genus, the Oak genus. The 
number of species in a genus is very various, — the Kentucky 
1See Warming and Potter Systematic Botany or Kerner and Oliver, vol. I, pp. 
616-790. 2 R. bulbosus. * R. acris. * R. multifidus. 5 R. abortivus. 
6 Fresh specimens or herbarium specimens will show this. 
