XI. FLOWERLESS PLANTS 



Systematic Botany. — The plant world is divided into many tribes or 

 groups. Any one who has visited a hothouse or a large garden is likely 

 to notice this fact. And not only are plants placed in large groups which 

 have some very conspicuous characters in common, but smaller groupings 

 can be made in which perhaps only a few plants having common characters 

 may be placed. If we plant a number of peas so that they will all germinate 

 under the same conditions of soil, temperature, and sunlight, the seedlings 

 that develop will each differ one from another in a slight degree. But in a 

 general way they will have many characters in common, as the shape of the 

 leaves, the possession of tendrils, form of the flower and fruit. The smallest 

 group of plants or animals having certain characters in common that make 

 them different from all other plants or animals is called a species. Individuals 

 of such species may differ slightly; indeed no two individuals are exactly 

 alike- It is known that in some cases seeds from plants which have thus 

 varied to a considerable degree may reproduce these variations in the young 

 plants. This fact is made use of by plant breeders to produce new kinds 

 of plants. 



Species are grouped together in a larger group called a genus. For 

 example many kinds of peas — the everlasting pea, the wild beach peas, 

 the sweet peas, and many others — are all grouped in one genus (called 

 Lathyrus or vetchling) because they have certain structural characteristics 

 in common. 



Nomenclature. — When we wish to identify a plant, we look it up 

 by means of its generic and specific names in much the same way that we 

 look up a name in a city directory. As in a directory the last name of the 

 person is placed first, as Jones, John, so we find the Latin name Phaseo- 

 lus given to the beans as a genus. Phaseolus vulgaris is the name of the 

 common bean; Phaseolus lunatus, the pole or lima bean; and Phaseolus 

 multiflorus, the scarlet runner. 



System of Classification Artificial. — Plant and animal genera are 

 brought together in still larger groups, the classification based on general like- 

 nesses in structure. Such groups are called, as they become successively 

 larger. Family or Tribe, Order, and Class. Thus the whole plant and animal 

 kingdom is artificially massed in separate divisions, the smallest of which con- 

 tains a few individuals very much alike ; and the largest of which contains 

 very many groups of individuals, the groups having some characters in 

 common. This is called a system of classification. 



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