BOTANICAL INTKODUCTION 49 



in which they are inserted. It must not be supposed that a 

 plant cannot belong to a family, because in one or more points 

 it does not completely agree with the characters of the family. 

 On the other hand, it is also unsafe to suppose that 

 because a plant has certain characters of a family or genus it 

 must necessarily be put in that family or genus. The student 

 cannot be too strongly warned against jumping at conclusions 

 of this sort. It is better, moreover, in identifying a specimen 

 to proceed by the method of "exhaustion" than by that of 

 identification, that is to say, it is safer to exclude first all 

 those families and genera to which the plant cannot belong, 

 before determining that to which it does belong. An example 

 will illustrate clearly the various classificatory divisions. 

 The native flax belongs to the 

 SPECIES : tenax. 



GENUS : Phonmum. 



FAMILY : Liliaceae. 



ORDER : Liliiflorae. 



SUB- CLASS : Monocotyledons. 

 CLASS : Angiosperms. 



KEY TO CLASSIFICATION." 



SUB-KINGDOM : Phanerogams or Flowering Plants. 



1. Ovules not enclosed in an Ovary Class 1. GYMNOSPERMAE, p. 46. 



2. Ovules enclosed in an Ovary Class 2. ANGIOSPERMAE , p. 46. 



(i) Seed with one seed-leaf, leaves generally 



parallel- veined. MONOCOTYLEDONS, p. 47. 



(ii) Seed with two seed-leaves, leaves 



generally netted-veined. DICOTYLEDONS, p. 47. 



ARTIFICIAL KEY TO THE ANGIOSPERMAE. 



SUB-CLASS I. : Monocotyledons ^ 

 , Perianth absent. 2. 



Perianth present. 3. 



, Climbing, shrubby plant. Leaves long, prickly. Freycinetia, p. 80. 



Erect water or marsh plants. \Typha. 



* N.B. It is to be remembered that in many cases this key is true only for New 

 ,land forms. 

 +Not further described. 5 



